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Controlled processivity in glycosyltransferases: A way to expand the enzymatic toolbox. Biotechnol Adv 2023; 63:108081. [PMID: 36529206 DOI: 10.1016/j.biotechadv.2022.108081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/20/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022]
Abstract
Glycosyltransferases (GT) catalyse the biosynthesis of complex carbohydrates which are the most abundant group of molecules in nature. They are involved in several key mechanisms such as cell signalling, biofilm formation, host immune system invasion or cell structure and this in both prokaryotic and eukaryotic cells. As a result, research towards complete enzyme mechanisms is valuable to understand and elucidate specific structure-function relationships in this group of molecules. In a next step this knowledge could be used in GT protein engineering, not only for rational drug design but also for multiple biotechnological production processes, such as the biosynthesis of hyaluronan, cellooligosaccharides or chitooligosaccharides. Generation of these poly- and/or oligosaccharides is possible due to a common feature of several of these GTs: processivity. Enzymatic processivity has the ability to hold on to the growing polymer chain and some of these GTs can even control the number of glycosyl transfers. In a first part, recent advances in understanding the mechanism of various processive enzymes are discussed. To this end, an overview is given of possible engineering strategies for the purpose of new industrial and fundamental applications. In the second part of this review, we focused on specific chain length-controlling mechanisms, i.e., key residues or conserved regions, and this for both eukaryotic and prokaryotic enzymes.
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2
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Zhang S, Li C, Gilbert RG, Malde AK. Understanding the Binding of Starch Fragments to Granule-Bound Starch Synthase. Biomacromolecules 2021; 22:4730-4737. [PMID: 34669391 DOI: 10.1021/acs.biomac.1c01012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Granule-bound starch synthase (GBSS) plays a major role, that of chain elongation, in the biosynthesis of amylose, a starch component with mostly (1 → 4)-α connected long chains of glucose with a few (1 → 6)-α branch points. Chain-length distributions (CLDs) of amylose affect functional properties, which can be controlled by changing appropriate residues on granule-bound starch synthase (GBSS). Knowing the binding of GBSS and amylose at a molecular level can help better determine the key amino acids on GBSS that affect CLDs of amylose for subsequent use in molecular engineering. Atomistic molecular dynamics simulations with explicit solvent and docking approaches were used in this study to build a model of the binding between rice GBSS and amylose. Amylose fragments containing 3-12 linearly linked glucose units were built to represent the starch fragments. The stability of the complexes, interactions between GBSS and sugars, and difference in structure/conformation of bound and free starch fragments were analyzed. The study found that starch/amylose fragments with 5 or 6 glucose units were suitable for modeling starch binding to GBSS. The removal of an interdomain disulfide on GBSS was found to affect both GBSS and starch stability. Key residues that could affect the binding ability were also indicated. This model can help rationalize the design of mutants and suggest ways to make single-point mutations, which could be used to develop plants producing starches with improved functional properties.
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Affiliation(s)
- Shaobo Zhang
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Joint International Research Laboratory of Agriculture and Agri-Product Safety, Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu, Yangzhou University, Yangzhou, Jiangsu 225009, China.,Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Cheng Li
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu, China.,School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Robert G Gilbert
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Joint International Research Laboratory of Agriculture and Agri-Product Safety, Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu, Yangzhou University, Yangzhou, Jiangsu 225009, China.,Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Alpeshkumar K Malde
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, QLD 4072, Australia
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Cui J, Tcherkez G. Potassium dependency of enzymes in plant primary metabolism. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 166:522-530. [PMID: 34174657 DOI: 10.1016/j.plaphy.2021.06.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
Potassium is a macroelement essential to many aspects of plant life, such as photosynthesis, phloem transport or cellular electrochemistry. Many enzymes in animals or microbes are known to be stimulated or activated by potassium (K+ ions). Several plant enzymes are also strictly K+-dependent, and this can be critical when plants are under K deficiency and thus intracellular K+ concentration is low. Although metabolic effects of low K conditions have been documented, there is presently no review focusing on roles of K+ for enzyme catalysis or activation in plants. In this mini-review, we compile the current knowledge on K+-requirement of plant enzymes and take advantage of structural data to present biochemical roles of K+. This information is instrumental to explain direct effects of low K+ content on metabolism and this is illustrated with recent metabolomics data.
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Affiliation(s)
- Jing Cui
- Research School of Biology, ANU Joint College of Sciences, Australian National University, 2601, Canberra, Australia
| | - Guillaume Tcherkez
- Research School of Biology, ANU Joint College of Sciences, Australian National University, 2601, Canberra, Australia; Institut de Recherche en Horticulture et Semences, INRAe Angers, Université d'Angers, 42 rue Georges Morel, 49070, Beaucouzé, France.
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4
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Seung D. Amylose in starch: towards an understanding of biosynthesis, structure and function. THE NEW PHYTOLOGIST 2020; 228:1490-1504. [PMID: 32767769 DOI: 10.1111/nph.16858] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/13/2020] [Indexed: 05/20/2023]
Abstract
Starch granules are composed of two distinct glucose polymers - amylose and amylopectin. Amylose constitutes 5-35% of most natural starches and has a major influence over starch properties in foods. Its synthesis and storage occurs within the semicrystalline amylopectin matrix of starch granules, this poses a great challenge for biochemical and structural analyses. However, the last two decades have seen vast progress in understanding amylose synthesis, including new insights into the action of GRANULE BOUND STARCH SYNTHASE (GBSS), the major glucosyltransferase that synthesises amylose, and the discovery of PROTEIN TARGETING TO STARCH1 (PTST1) that targets GBSS to starch granules. Advances in analytical techniques have resolved the fine structure of amylose, raising new questions on how structure is determined during biosynthesis. Furthermore, the discovery of wild plants that do not produce amylose revives a long-standing question of why starch granules contain amylose, rather than amylopectin alone. Overall, these findings contribute towards a full understanding of amylose biosynthesis, structure and function that will be essential for future approaches to improve starch quality in crops.
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Affiliation(s)
- David Seung
- John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
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Ancín M, Larraya L, Fernández-San Millán A, Veramendi J, Burch-Smith T, Farran I. NTRC and Thioredoxin f Overexpression Differentially Induces Starch Accumulation in Tobacco Leaves. PLANTS 2019; 8:plants8120543. [PMID: 31779140 PMCID: PMC6963466 DOI: 10.3390/plants8120543] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/18/2019] [Accepted: 11/20/2019] [Indexed: 11/16/2022]
Abstract
Thioredoxin (Trx) f and NADPH-dependent Trx reductase C (NTRC) have both been proposed as major redox regulators of starch metabolism in chloroplasts. However, little is known regarding the specific role of each protein in this complex mechanism. To shed light on this point, tobacco plants that were genetically engineered to overexpress the NTRC protein from the chloroplast genome were obtained and compared to previously generated Trx f-overexpressing transplastomic plants. Likewise, we investigated the impact of NTRC and Trx f deficiency on starch metabolism by generating Nicotiana benthamiana plants that were silenced for each gene. Our results demonstrated that NTRC overexpression induced enhanced starch accumulation in tobacco leaves, as occurred with Trx f. However, only Trx f silencing leads to a significant decrease in the leaf starch content. Quantitative analysis of enzyme activities related to starch synthesis and degradation were determined in all of the genotypes. Zymographic analyses were additionally performed to compare the amylolytic enzyme profiles of both transplastomic tobacco plants. Our findings indicated that NTRC overexpression promotes the accumulation of transitory leaf starch as a consequence of a diminished starch turnover during the dark period, which seems to be related to a significant reductive activation of ADP-glucose pyrophosphorylase and/or a deactivation of a putative debranching enzyme. On the other hand, increased starch content in Trx f-overexpressing plants was connected to an increase in the capacity of soluble starch synthases during the light period. Taken together, these results suggest that NTRC and the ferredoxin/Trx system play distinct roles in starch turnover.
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Affiliation(s)
- María Ancín
- Institute for Multidisciplinary Research in Applied Biology, UPNA, 31006 Pamplona, Spain; (M.A.); (L.L.); (A.F.-S.M.); (J.V.)
| | - Luis Larraya
- Institute for Multidisciplinary Research in Applied Biology, UPNA, 31006 Pamplona, Spain; (M.A.); (L.L.); (A.F.-S.M.); (J.V.)
| | - Alicia Fernández-San Millán
- Institute for Multidisciplinary Research in Applied Biology, UPNA, 31006 Pamplona, Spain; (M.A.); (L.L.); (A.F.-S.M.); (J.V.)
| | - Jon Veramendi
- Institute for Multidisciplinary Research in Applied Biology, UPNA, 31006 Pamplona, Spain; (M.A.); (L.L.); (A.F.-S.M.); (J.V.)
| | - Tessa Burch-Smith
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA;
| | - Inmaculada Farran
- Institute for Multidisciplinary Research in Applied Biology, UPNA, 31006 Pamplona, Spain; (M.A.); (L.L.); (A.F.-S.M.); (J.V.)
- Correspondence: ; Tel.: +34-948-168-034
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Rapid Visco Analyser (RVA) as a Tool for Measuring Starch-Related Physiochemical Properties in Cereals: a Review. FOOD ANAL METHOD 2019. [DOI: 10.1007/s12161-019-01581-w] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Wilkens C, Svensson B, Møller MS. Functional Roles of Starch Binding Domains and Surface Binding Sites in Enzymes Involved in Starch Biosynthesis. FRONTIERS IN PLANT SCIENCE 2018; 9:1652. [PMID: 30483298 PMCID: PMC6243121 DOI: 10.3389/fpls.2018.01652] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/24/2018] [Indexed: 05/07/2023]
Abstract
Biosynthesis of starch is catalyzed by a cascade of enzymes. The activity of a large number of these enzymes depends on interaction with polymeric substrates via carbohydrate binding sites, which are situated outside of the catalytic site and its immediate surroundings including the substrate-binding crevice. Such secondary binding sites can belong to distinct starch binding domains (SBDs), classified as carbohydrate binding modules (CBMs), or be surface binding sites (SBSs) exposed on the surface of catalytic domains. Currently in the Carbohydrate-Active enZYmes (CAZy) database SBDs are found in 13 CBM families. Four of these families; CBM20, CBM45, CBM48, and CBM53 are represented in enzymes involved in starch biosynthesis, namely starch synthases, branching enzymes, isoamylases, glucan, water dikinases, and α-glucan phosphatases. A critical role of the SBD in activity has not been demonstrated for any of these enzymes. Among the well-characterized SBDs important for starch biosynthesis are three CBM53s of Arabidopsis thaliana starch synthase III, which have modest affinity. SBSs, which are overall less widespread than SBDs, have been reported in some branching enzymes, isoamylases, synthases, phosphatases, and phosphorylases active in starch biosynthesis. SBSs appear to exert roles similar to CBMs. SBSs, however, have also been shown to modulate specificity for example by discriminating the length of chains transferred by branching enzymes. Notably, the difference in rate of occurrence between SBDs and SBSs may be due to lack of awareness of SBSs. Thus, SBSs as opposed to CBMs are not recognized at the protein sequence level, which hampers their identification. Moreover, only a few SBSs in enzymes involved in starch biosynthesis have been functionally characterized, typically by structure-guided site-directed mutagenesis. The glucan phosphatase Like SEX4 2 from A. thaliana has two SBSs with weak affinity for β-cyclodextrin, amylose and amylopectin, which were indicated by mutational analysis to be more important than the active site for initial substrate recognition. The present review provides an update on occurrence of functional SBDs and SBSs in enzymes involved in starch biosynthesis.
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Affiliation(s)
- Casper Wilkens
- Enzyme Technology, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Marie Sofie Møller
- Enzyme and Protein Chemistry, Department of Bioengineering and Biomedicine, Technical University of Denmark, Lyngby, Denmark
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8
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Xie Y, Barb AW, Hennen-Bierwagen TA, Myers AM. Direct Determination of the Site of Addition of Glucosyl Units to Maltooligosaccharide Acceptors Catalyzed by Maize Starch Synthase I. FRONTIERS IN PLANT SCIENCE 2018; 9:1252. [PMID: 30233610 PMCID: PMC6127246 DOI: 10.3389/fpls.2018.01252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 08/07/2018] [Indexed: 06/08/2023]
Abstract
Starch synthase (SS) (ADP-glucose:1,4-α-D-glucan 4-α-D-glucosyltransferase) elongates α-(1→4)-linked linear glucans within plastids to generate the storage polymers that constitute starch granules. Multiple SS classes are conserved throughout the plant kingdom, indicating that each provides a unique function responsible for evolutionary selection. Evidence has been presented arguing for addition of glucosyl units from the ADPglucose donor to either the reducing end or the non-reducing end of the acceptor substrate, although until recently direct evidence addressing this question was not available. Characterization of newly incorporated glucosyl units determined that recombinant maize (Zea mays L.) SSIIa elongates its substrates at the non-reducing end. However, the possibility remained that other SSs might utilize distinct mechanisms, and that one or more of the conserved enzyme classes could elongate acceptors at the reducing end. This study characterized the reaction mechanism of recombinant maize SSI regarding its addition site. Newly incorporated residues were labeled with 13C, and reducing ends of the elongation products were labeled by chemical derivitization. Electrospray ionization-tandem mass spectroscopy traced the two parameters, i.e., the newly added residue and the reducing end. The results determined that SSI elongates glucans at the non-reducing end. The study also confirmed previous findings showing recombinant SSI can generate glucans of at least 25 units, that it is active using acceptors as short as maltotriose, that recombinant forms of the enzyme absolutely require an acceptor for activity, and that it is not saturable with maltooligosaccharide acceptor substrates.
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Affiliation(s)
- Ying Xie
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
- College of Agronomy, Sichuan Agricultural University, Chengdu, China
| | - Adam W. Barb
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Tracie A. Hennen-Bierwagen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Alan M. Myers
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, United States
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Qu J, Xu S, Zhang Z, Chen G, Zhong Y, Liu L, Zhang R, Xue J, Guo D. Evolutionary, structural and expression analysis of core genes involved in starch synthesis. Sci Rep 2018; 8:12736. [PMID: 30143668 PMCID: PMC6109180 DOI: 10.1038/s41598-018-30411-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/30/2018] [Indexed: 01/29/2023] Open
Abstract
Starch is the main storage carbohydrate in plants and an important natural resource for food, feed and industrial raw materials. However, the details regarding the pathway for starch biosynthesis and the diversity of biosynthetic enzymes involved in this process are poorly understood. This study uses a comprehensive phylogenetic analysis of 74 sequenced plant genomes to revisit the evolutionary history of the genes encoding ADP-glucose pyrophosphorylase (AGPase), starch synthase (SS), starch branching enzyme (SBE) and starch de-branching enzyme (DBE). Additionally, the protein structures and expression patterns of these four core genes in starch biosynthesis were studied to determine their functional differences. The results showed that AGPase, SS, SBE and DBE have undergone complicated evolutionary processes in plants and that gene/genome duplications are responsible for the observed differences in isoform numbers. A structure analysis of these proteins suggested that the deletion/mutation of amino acids in some active sites resulted in not only structural variation but also sub-functionalization or neo-functionalization. Expression profiling indicated that AGPase-, SS-, SBE- and DBE-encoding genes exhibit spatio-temporally divergent expression patterns related to the composition of functional complexes in starch biosynthesis. This study provides a comprehensive atlas of the starch biosynthetic pathway, and these data should support future studies aimed at increasing understanding of starch biosynthesis and the functional evolutionary divergence of AGPase, SS, SBE, and DBE in plants.
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Affiliation(s)
- Jianzhou Qu
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Shutu Xu
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Zhengquan Zhang
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Guangzhou Chen
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Yuyue Zhong
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Linsan Liu
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Renhe Zhang
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China
| | - Jiquan Xue
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China.
| | - Dongwei Guo
- The key Laboratory of Biology and Genetics Improvement of Maize in Arid Area of Northwest Region, Ministry of Agriculture, College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
- Maize Engineering Technology Research Centre of Shaanxi Province, Yangling, 712100, Shaanxi, China.
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10
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Li Q, Liu X, Zhang C, Jiang L, Jiang M, Zhong M, Fan X, Gu M, Liu Q. Rice Soluble Starch Synthase I: Allelic Variation, Expression, Function, and Interaction With Waxy. FRONTIERS IN PLANT SCIENCE 2018; 9:1591. [PMID: 30483281 PMCID: PMC6243471 DOI: 10.3389/fpls.2018.01591] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 10/15/2018] [Indexed: 05/07/2023]
Abstract
Starch, which is composed of amylose and amylopectin, is the key determinant of rice quality. Amylose is regulated by the Waxy (Wx) gene, whereas amylopectin is coordinated by various enzymes including eight soluble starch synthases (SSSs), of which SSSI accounts for ∼70% of the total SSS activity in cereal endosperm. Although great progress has been made in understanding SSSI gene expression and function, allelic variation and its effects on gene expression, rice physicochemical properties and qualities, and interactions with the Wx gene remain unclear. Herein, SSSI nucleotide polymorphisms were analyzed in 165 rice varieties using five distinct molecular markers, three of which reside in an SSSI promoter and might account for a higher expression of the SSSIi allele in indica ssp. than of the SSSIj allele in japonica ssp. The results of SSSI promoter-Beta-Glucuronidase (β-GUS) analysis were consistent with the expression results. Moreover, analysis of near isogenic lines (NILs) in the Nipponbare (Nip) background showed that Nip (SSSIi ) and Nip (SSSIj ) differed in their thermal properties, gel consistency (GC), and granule crystal structure. Knockdown of SSSI expression using the SSSI-RNA interference (RNAi) construct in both japonica and indica backgrounds caused consistent changes in most tested physicochemical characteristics except GC. Moreover, taste value analysis (TVA) showed that introduction of the SSSI allele in indica or knockdown of SSSI expression in japonica cultivars significantly reduced the comprehensive taste value, which was consistent with the superior taste of japonica against indica. Furthermore, to test the potential interaction between SSSI and different Wx alleles, three NILs within the Wx locus were generated in the indica cv. Longtefu (LTF) background, which were designated as LTF (Wxa ), LTF (Wxb ), and LTF (wx). The SSSI-RNAi construct was also introduced into these three NILs, and physiochemical analysis confirmed that the knockdown of SSSI significantly increased the rice apparent amylose content (AAC) only in the Wxa and Wxb background and caused different changes in GC in the NILs. Therefore, the effect of SSSI variation on rice quality also depends on its crosstalk with other factors, especially the Wx gene. These findings provide fundamental knowledge for future breeding of rice with premium eating and cooking qualities.
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Affiliation(s)
- Qianfeng Li
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province, Joint International Research Laboratory of Agriculture & Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Xinyan Liu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Changquan Zhang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province, Joint International Research Laboratory of Agriculture & Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
| | - Li Jiang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Meiyan Jiang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Min Zhong
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Xiaolei Fan
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Minghong Gu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Qiaoquan Liu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Key Laboratory of Crop Genetics and Physiology of Jiangsu Province/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
- Co-Innovation Center for Modern Production Technology of Grain Crops of Jiangsu Province, Joint International Research Laboratory of Agriculture & Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou, China
- *Correspondence: Qiaoquan Liu,
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11
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Nielsen MM, Ruzanski C, Krucewicz K, Striebeck A, Cenci U, Ball SG, Palcic MM, Cuesta-Seijo JA. Crystal Structures of the Catalytic Domain of Arabidopsis thaliana Starch Synthase IV, of Granule Bound Starch Synthase From CLg1 and of Granule Bound Starch Synthase I of Cyanophora paradoxa Illustrate Substrate Recognition in Starch Synthases. FRONTIERS IN PLANT SCIENCE 2018; 9:1138. [PMID: 30123236 PMCID: PMC6086201 DOI: 10.3389/fpls.2018.01138] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/13/2018] [Indexed: 05/20/2023]
Abstract
Starch synthases (SSs) are responsible for depositing the majority of glucoses in starch. Structural knowledge on these enzymes that is available from the crystal structures of rice granule bound starch synthase (GBSS) and barley SSI provides incomplete information on substrate binding and active site architecture. Here we report the crystal structures of the catalytic domains of SSIV from Arabidopsis thaliana, of GBSS from the cyanobacterium CLg1 and GBSSI from the glaucophyte Cyanophora paradoxa, with all three bound to ADP and the inhibitor acarbose. The SSIV structure illustrates in detail the modes of binding for both donor and acceptor in a plant SS. CLg1GBSS contains, in the same crystal structure, examples of molecules with and without bound acceptor, which illustrates the conformational changes induced upon acceptor binding that presumably precede catalytic activity. With structures available from several isoforms of plant and non-plant SSs, as well as the closely related bacterial glycogen synthases, we analyze, at the structural level, the common elements that define a SS, the elements that are necessary for substrate binding and singularities of the GBSS family that could underlie its processivity. While the phylogeny of the SSIII/IV/V has been recently discussed, we now further report the detailed evolutionary history of the GBSS/SSI/SSII type of SSs enlightening the origin of the GBSS enzymes used in our structural analysis.
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Affiliation(s)
| | - Christian Ruzanski
- Carlsberg Research Laboratory, Copenhagen, Denmark
- † Present address: Christian Ruzanski, Novo Nordisk A/S, Måløv, Denmark Monica M. Palcic, Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | | | | | - Ugo Cenci
- UMR8576 CNRS-USTL, Unité de Glycobiologie Structurale et Fonctionnelle, Université des Sciences et Technologies de Lille, Villeneuve-d’Ascq, France
| | - Steven G. Ball
- UMR8576 CNRS-USTL, Unité de Glycobiologie Structurale et Fonctionnelle, Université des Sciences et Technologies de Lille, Villeneuve-d’Ascq, France
| | - Monica M. Palcic
- Carlsberg Research Laboratory, Copenhagen, Denmark
- † Present address: Christian Ruzanski, Novo Nordisk A/S, Måløv, Denmark Monica M. Palcic, Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Jose A. Cuesta-Seijo
- Carlsberg Research Laboratory, Copenhagen, Denmark
- *Correspondence: Jose A. Cuesta-Seijo,
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12
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Nazarian-Firouzabadi F, Visser RGF. Potato starch synthases: Functions and relationships. Biochem Biophys Rep 2017; 10:7-16. [PMID: 29114568 PMCID: PMC5637242 DOI: 10.1016/j.bbrep.2017.02.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 01/28/2023] Open
Abstract
Starch, a very compact form of glucose units, is the most abundant form of storage polyglucan in nature. The starch synthesis pathway is among the central biochemical pathways, however, our understanding of this important pathway regarding genetic elements controlling this pathway, is still insufficient. Starch biosynthesis requires the action of several enzymes. Soluble starch synthases (SSs) are a group of key players in starch biosynthesis which have proven their impact on different aspects of the starch biosynthesis and functionalities. These enzymes have been studied in different plant species and organs in detail, however, there seem to be key differences among species regarding their contributions to the starch synthesis. In this review, we consider an update on various SSs with an emphasis on potato SSs as a model for storage organs. The genetics and regulatory mechanisms of potato starch synthases will be highlighted. Different aspects of various isoforms of SSs are also discussed.
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Affiliation(s)
- Farhad Nazarian-Firouzabadi
- Agronomy and Plant Breeding Department, Faculty of Agriculture, Lorestan University, P.O.Box 465, Khorramabad, Iran
| | - Richard G F Visser
- Plant Breeding, Wageningen University & Research, P.O. Box 386, 6700 AJ, Wageningen, The Netherlands
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13
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Hebelstrup KH, Nielsen MM, Carciofi M, Andrzejczak O, Shaik SS, Blennow A, Palcic MM. Waxy and non-waxy barley cultivars exhibit differences in the targeting and catalytic activity of GBSS1a. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:931-941. [PMID: 28199682 PMCID: PMC5441850 DOI: 10.1093/jxb/erw503] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Amylose synthesis is strictly associated with activity of granule-bound starch synthase (GBSS) enzymes. Among several crops there are cultivars containing starch types with either little or no amylose known as near-waxy or waxy. This (near) amylose-free phenotype is associated with a single locus (waxy) which has been mapped to GBSS-type genes in different crops. Most waxy varieties are a result of either low or no expression of a GBSS gene. However, there are some waxy cultivars where the GBSS enzymes are expressed normally. For these types, single nucleotide polymorphisms have been hypothesized to represent amino-acid substitutions leading to loss of catalytic activity. We here confirm that the HvGBSSIa enzyme from one such waxy barley variety, CDC_Alamo, has a 90% reduction in catalytic activity. We also engineered plants with expression of transgenic C-terminal green fluorescent protein-tagged HvGBSSIa of both the non-waxy type and of the CDC_Alamo type to monitor their subcellular localization patterns in grain endosperm. HvGBSSIa from non-waxy cultivars was found to localize in discrete concentric spheres strictly within starch granules. In contrast, HvGBSSIa from waxy CDC_Alamo showed deficient starch targeting mostly into unknown subcellular bodies of 0.5-3 µm in size, indicating that the waxy phenotype of CDC_Alamo is associated with deficient targeting of HvGBSSIa into starch granules.
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Affiliation(s)
- Kim H Hebelstrup
- Department of Molecular Biology and Genetics, Section of Crop Genetics and Biotechnology, Aarhus University, Forsøgsvej 1, 4200 Slagelse, Denmark
| | | | - Massimiliano Carciofi
- Department of Molecular Biology and Genetics, Section of Crop Genetics and Biotechnology, Aarhus University, Forsøgsvej 1, 4200 Slagelse, Denmark
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 København V, Denmark
| | - Olga Andrzejczak
- Department of Molecular Biology and Genetics, Section of Crop Genetics and Biotechnology, Aarhus University, Forsøgsvej 1, 4200 Slagelse, Denmark
| | - Shahnoor Sultana Shaik
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Andreas Blennow
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Monica M Palcic
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, DK-1799 København V, Denmark
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14
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Larson ME, Falconer DJ, Myers AM, Barb AW. Direct Characterization of the Maize Starch Synthase IIa Product Shows Maltodextrin Elongation Occurs at the Non-reducing End. J Biol Chem 2016; 291:24951-24960. [PMID: 27733678 DOI: 10.1074/jbc.m116.754705] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 10/06/2016] [Indexed: 11/06/2022] Open
Abstract
A comprehensive description of starch biosynthesis and granule assembly remains undefined despite the central nature of starch as an energy storage molecule in plants and as a fundamental calorie source for many animals. Multiple theories regarding the starch synthase (SS)-catalyzed assembly of (α1-4)-linked d-glucose molecules into maltodextrins generally agree that elongation occurs at the non-reducing terminus based on the degradation of radiolabeled maltodextrins, although recent reports challenge this hypothesis. Surprisingly, a direct analysis of the SS catalytic product has not been reported, to our knowledge. We expressed and characterized recombinant Zea mays SSIIa and prepared pure ADP-[13CU]glucose in a one-pot enzymatic synthesis to address the polarity of maltodextrin chain elongation. We synthesized maltoheptaose (degree of polymerization 7) using ADP-[13CU]glucose, maltohexaose (degree of polymerization 6), and SSIIa. Product analysis by ESI-MS revealed that the [13CU]glucose unit was added to the non-reducing end of the growing chain, and SSIIa demonstrated a >7,850-fold preference for addition to the non-reducing end versus the reducing end. Independent analysis of [13CU]glucose added to maltohexaose by SSIIa using solution NMR spectroscopy confirmed the polarity of maltodextrin chain elongation.
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Affiliation(s)
- Mark E Larson
- From the Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Daniel J Falconer
- From the Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Alan M Myers
- From the Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
| | - Adam W Barb
- From the Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
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15
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Møller MS, Svensson B. Structural biology of starch-degrading enzymes and their regulation. Curr Opin Struct Biol 2016; 40:33-42. [DOI: 10.1016/j.sbi.2016.07.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 07/06/2016] [Accepted: 07/06/2016] [Indexed: 02/05/2023]
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16
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Seung D, Lu KJ, Stettler M, Streb S, Zeeman SC. Degradation of Glucan Primers in the Absence of Starch Synthase 4 Disrupts Starch Granule Initiation in Arabidopsis. J Biol Chem 2016; 291:20718-28. [PMID: 27458017 PMCID: PMC5034061 DOI: 10.1074/jbc.m116.730648] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Indexed: 01/01/2023] Open
Abstract
Arabidopsis leaf chloroplasts typically contain five to seven semicrystalline starch granules. It is not understood how the synthesis of each granule is initiated or how starch granule number is determined within each chloroplast. An Arabidopsis mutant lacking the glucosyl-transferase, STARCH SYNTHASE 4 (SS4) is impaired in its ability to initiate starch granules; its chloroplasts rarely contain more than one large granule, and the plants have a pale appearance and reduced growth. Here we report that the chloroplastic α-amylase AMY3, a starch-degrading enzyme, interferes with granule initiation in the ss4 mutant background. The amy3 single mutant is similar in phenotype to the wild type under normal growth conditions, with comparable numbers of starch granules per chloroplast. Interestingly, the ss4 mutant displays a pleiotropic reduction in the activity of AMY3. Remarkably, complete abolition of AMY3 (in the amy3 ss4 double mutant) increases the number of starch granules produced in each chloroplast, suppresses the pale phenotype of ss4, and nearly restores normal growth. The amy3 mutation also restores starch synthesis in the ss3 ss4 double mutant, which lacks STARCH SYNTHASE 3 (SS3) in addition to SS4. The ss3 ss4 line is unable to initiate any starch granules and is thus starchless. We suggest that SS4 plays a key role in granule initiation, allowing it to proceed in a way that avoids premature degradation of primers by starch hydrolases, such as AMY3.
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Affiliation(s)
- David Seung
- From the Institute for Agricultural Sciences, ETH Zurich, 8092 Zürich, Switzerland
| | - Kuan-Jen Lu
- From the Institute for Agricultural Sciences, ETH Zurich, 8092 Zürich, Switzerland
| | - Michaela Stettler
- From the Institute for Agricultural Sciences, ETH Zurich, 8092 Zürich, Switzerland
| | - Sebastian Streb
- From the Institute for Agricultural Sciences, ETH Zurich, 8092 Zürich, Switzerland
| | - Samuel C Zeeman
- From the Institute for Agricultural Sciences, ETH Zurich, 8092 Zürich, Switzerland
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17
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Abstract
Starch-rich crops form the basis of our nutrition, but plants have still to yield all their secrets as to how they make this vital substance. Great progress has been made by studying both crop and model systems, and we approach the point of knowing the enzymatic machinery responsible for creating the massive, insoluble starch granules found in plant tissues. Here, we summarize our current understanding of these biosynthetic enzymes, highlighting recent progress in elucidating their specific functions. Yet, in many ways we have only scratched the surface: much uncertainty remains about how these components function together and are controlled. We flag-up recent observations suggesting a significant degree of flexibility during the synthesis of starch and that previously unsuspected non-enzymatic proteins may have a role. We conclude that starch research is not yet a mature subject and that novel experimental and theoretical approaches will be important to advance the field.
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Affiliation(s)
- Barbara Pfister
- Department of Biology, ETH Zurich, 8092, Zurich, Switzerland
| | - Samuel C Zeeman
- Department of Biology, ETH Zurich, 8092, Zurich, Switzerland.
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18
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Raynaud S, Ragel P, Rojas T, Mérida Á. The N-terminal Part of Arabidopsis thaliana Starch Synthase 4 Determines the Localization and Activity of the Enzyme. J Biol Chem 2016; 291:10759-71. [PMID: 26969163 DOI: 10.1074/jbc.m115.698332] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Indexed: 01/22/2023] Open
Abstract
Starch synthase 4 (SS4) plays a specific role in starch synthesis because it controls the number of starch granules synthesized in the chloroplast and is involved in the initiation of the starch granule. We showed previously that SS4 interacts with fibrillins 1 and is associated with plastoglobules, suborganelle compartments physically attached to the thylakoid membrane in chloroplasts. Both SS4 localization and its interaction with fibrillins 1 were mediated by the N-terminal part of SS4. Here we show that the coiled-coil region within the N-terminal portion of SS4 is involved in both processes. Elimination of this region prevents SS4 from binding to fibrillins 1 and alters SS4 localization in the chloroplast. We also show that SS4 forms dimers, which depends on a region located between the coiled-coil region and the glycosyltransferase domain of SS4. This region is highly conserved between all SS4 enzymes sequenced to date. We show that the dimerization seems to be necessary for the activity of the enzyme. Both dimerization and the functionality of the coiled-coil region are conserved among SS4 proteins from phylogenetically distant species, such as Arabidopsis and Brachypodium This finding suggests that the mechanism of action of SS4 is conserved among different plant species.
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Affiliation(s)
- Sandy Raynaud
- From the Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas, University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain
| | - Paula Ragel
- From the Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas, University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain
| | - Tomás Rojas
- From the Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas, University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain
| | - Ángel Mérida
- From the Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas, University of Sevilla, Avenida Américo Vespucio 49, 41092 Sevilla, Spain
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19
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Chen Y, Bao J. Underlying Mechanisms of Zymographic Diversity in Starch Synthase I and Pullulanase in Rice-Developing Endosperm. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:2030-7. [PMID: 26860852 DOI: 10.1021/acs.jafc.5b06030] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Amylopectin is synthesized by the coordinated actions of many (iso)enzymes, including ADP-glucose pyrophosphorylase (AGPase), starch synthases (SSs), branching enzymes (BEs), and debranching enzymes (DBEs). Here, two polymorphic forms of starch synthase I (SSI) and pullulanase (PUL) in rice-developing seeds, designated as SSI-1/SSI-2 and PUL-1/PUL-2, were discovered for the first time by zymographic analysis. The SSI and PUL polymorphisms were strongly associated with the SSI microsatellite marker (p = 3.6 × 10(-37)) and PUL insertion/deletion (InDel) markers (p < 3.6 × 10(-51)). Western blotting and mass spectrometric analysis confirmed that the polymorphic bands were truly the SSI and PUL enzymes. Only one non-synonymous variation in SSI DNA sequence (the SNP A/G) causing the change of the amino acid K438 to E438 was observed, which coincided well with the polymorphic forms of SSI. Nine non-synonymous variations were found between PUL-1 and PUL-2. Two non-synonymous variations of PUL (F316L and D770E) were identified by mass spectrometric analysis, but all of the variations did not change the structure of PUL. The co-immunoprecipitation results revealed the differences in protein-protein interaction patterns, i.e., strong or weaker signals of SSI-BEI and SSI-BEIIb, between the two forms of SSI. The results will enhance our understanding of SSI and PUL properties and provide helpful information to understand their functions in starch biosynthesis in rice endosperm.
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Affiliation(s)
- Yaling Chen
- Institute of Nuclear Agricultural Science, College of Agriculture and Biotechnology, Zhejiang University , Huajiachi Campus, Hangzhou, Zhejiang 310029, People's Republic of China
| | - Jinsong Bao
- Institute of Nuclear Agricultural Science, College of Agriculture and Biotechnology, Zhejiang University , Huajiachi Campus, Hangzhou, Zhejiang 310029, People's Republic of China
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20
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Huang B, Keeling PL, Hennen-Bierwagen TA, Myers AM. Comparative in vitro analyses of recombinant maize starch synthases SSI, SSIIa, and SSIII reveal direct regulatory interactions and thermosensitivity. Arch Biochem Biophys 2016; 596:63-72. [PMID: 26940263 DOI: 10.1016/j.abb.2016.02.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 02/06/2016] [Accepted: 02/28/2016] [Indexed: 11/19/2022]
Abstract
Starch synthases SSI, SSII, and SSIII function in assembling the amylopectin component of starch, but their specific roles and means of coordination are not fully understood. Genetic analyses indicate regulatory interactions among SS classes, and physical interactions among them are known. The N terminal extension of cereal SSIII, comprising up to 1200 residues beyond the catalytic domain, is responsible at least in part for these interactions. Recombinant maize SSI, SSIIa, and full-length or truncated SSIII, were tested for functional interactions regarding enzymatic activity. Amino-terminal truncated SSIII exhibited reduced activity compared to full-length enzyme, and addition of the N terminus to the truncated protein stimulated catalytic activity. SSIII and SSI displayed a negative interaction that reduced total activity in a reconstituted system. These data demonstrate that SSIII is both a catalytic and regulatory factor. SSIII activity was reduced by approximately 50% after brief incubation at 45 °C, suggesting a role in reduced starch accumulation during growth in high temperatures. Buffer effects were tested to address a current debate regarding the SS mechanism. Glucan stimulated the SSIIa and SSIII reaction rate regardless of the buffer system, supporting the accepted mechanism in which glucosyl units are added to exogenous primer substrates.
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Affiliation(s)
- Binquan Huang
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Peter L Keeling
- Center for Biorenewable Chemicals, 1140K Biorenewables Research Laboratory, Iowa State University, Ames, IA 50011, USA
| | - Tracie A Hennen-Bierwagen
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Alan M Myers
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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21
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Cuesta-Seijo JA, Nielsen MM, Ruzanski C, Krucewicz K, Beeren SR, Rydhal MG, Yoshimura Y, Striebeck A, Motawia MS, Willats WGT, Palcic MM. In vitro Biochemical Characterization of All Barley Endosperm Starch Synthases. FRONTIERS IN PLANT SCIENCE 2016; 6:1265. [PMID: 26858729 PMCID: PMC4730117 DOI: 10.3389/fpls.2015.01265] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 12/27/2015] [Indexed: 05/18/2023]
Abstract
Starch is the main storage polysaccharide in cereals and the major source of calories in the human diet. It is synthesized by a panel of enzymes including five classes of starch synthases (SSs). While the overall starch synthase (SS) reaction is known, the functional differences between the five SS classes are poorly understood. Much of our knowledge comes from analyzing mutant plants with altered SS activities, but the resulting data are often difficult to interpret as a result of pleitropic effects, competition between enzymes, overlaps in enzyme activity and disruption of multi-enzyme complexes. Here we provide a detailed biochemical study of the activity of all five classes of SSs in barley endosperm. Each enzyme was produced recombinantly in E. coli and the properties and modes of action in vitro were studied in isolation from other SSs and other substrate modifying activities. Our results define the mode of action of each SS class in unprecedented detail; we analyze their substrate selection, temperature dependence and stability, substrate affinity and temporal abundance during barley development. Our results are at variance with some generally accepted ideas about starch biosynthesis and might lead to the reinterpretation of results obtained in planta. In particular, they indicate that granule bound SS is capable of processive action even in the absence of a starch matrix, that SSI has no elongation limit, and that SSIV, believed to be critical for the initiation of starch granules, has maltoligosaccharides and not polysaccharides as its preferred substrates.
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Affiliation(s)
| | | | | | | | | | - Maja G. Rydhal
- Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Copenhagen, Denmark
| | | | | | - Mohammed S. Motawia
- Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Copenhagen, Denmark
| | - William G. T. Willats
- Department of Plant and Environmental Sciences, University of CopenhagenFrederiksberg, Copenhagen, Denmark
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22
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Wilkens C, Auger KD, Anderson NT, Meekins DA, Raththagala M, Abou Hachem M, Payne CM, Gentry MS, Svensson B. Plant α‐glucan phosphatases SEX4 and LSF2 display different affinity for amylopectin and amylose. FEBS Lett 2016; 590:118-28. [DOI: 10.1002/1873-3468.12027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 11/23/2015] [Accepted: 11/23/2015] [Indexed: 01/01/2023]
Affiliation(s)
- Casper Wilkens
- Enzyme and Protein Chemistry Department of Systems Biology Technical University of Denmark Kongens Lyngby Denmark
| | - Kyle D. Auger
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology University of Kentucky Lexington KY USA
| | - Nolan T. Anderson
- Department of Chemical and Materials Engineering University of Kentucky Lexington KY USA
| | - David A. Meekins
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology University of Kentucky Lexington KY USA
| | - Madushi Raththagala
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology University of Kentucky Lexington KY USA
| | - Maher Abou Hachem
- Enzyme and Protein Chemistry Department of Systems Biology Technical University of Denmark Kongens Lyngby Denmark
| | - Christina M. Payne
- Department of Chemical and Materials Engineering University of Kentucky Lexington KY USA
| | - Matthew S. Gentry
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology University of Kentucky Lexington KY USA
| | - Birte Svensson
- Enzyme and Protein Chemistry Department of Systems Biology Technical University of Denmark Kongens Lyngby Denmark
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23
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Skryhan K, Cuesta-Seijo JA, Nielsen MM, Marri L, Mellor SB, Glaring MA, Jensen PE, Palcic MM, Blennow A. The Role of Cysteine Residues in Redox Regulation and Protein Stability of Arabidopsis thaliana Starch Synthase 1. PLoS One 2015; 10:e0136997. [PMID: 26367870 PMCID: PMC4569185 DOI: 10.1371/journal.pone.0136997] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 08/11/2015] [Indexed: 11/23/2022] Open
Abstract
Starch biosynthesis in Arabidopsis thaliana is strictly regulated. In leaf extracts, starch synthase 1 (AtSS1) responds to the redox potential within a physiologically relevant range. This study presents data testing two main hypotheses: 1) that specific thiol-disulfide exchange in AtSS1 influences its catalytic function 2) that each conserved Cys residue has an impact on AtSS1 catalysis. Recombinant AtSS1 versions carrying combinations of cysteine-to-serine substitutions were generated and characterized in vitro. The results demonstrate that AtSS1 is activated and deactivated by the physiological redox transmitters thioredoxin f1 (Trxf1), thioredoxin m4 (Trxm4) and the bifunctional NADPH-dependent thioredoxin reductase C (NTRC). AtSS1 displayed an activity change within the physiologically relevant redox range, with a midpoint potential equal to -306 mV, suggesting that AtSS1 is in the reduced and active form during the day with active photosynthesis. Cys164 and Cys545 were the key cysteine residues involved in regulatory disulfide formation upon oxidation. A C164S_C545S double mutant had considerably decreased redox sensitivity as compared to wild type AtSS1 (30% vs 77%). Michaelis-Menten kinetics and molecular modeling suggest that both cysteines play important roles in enzyme catalysis, namely, Cys545 is involved in ADP-glucose binding and Cys164 is involved in acceptor binding. All the other single mutants had essentially complete redox sensitivity (98–99%). In addition of being part of a redox directed activity “light switch”, reactivation tests and low heterologous expression levels indicate that specific cysteine residues might play additional roles. Specifically, Cys265 in combination with Cys164 can be involved in proper protein folding or/and stabilization of translated protein prior to its transport into the plastid. Cys442 can play an important role in enzyme stability upon oxidation. The physiological and phylogenetic relevance of these findings is discussed.
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Affiliation(s)
- Katsiaryna Skryhan
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | | | - Morten M. Nielsen
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Lucia Marri
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | - Silas B. Mellor
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Mikkel A. Glaring
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Poul E. Jensen
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Monica M. Palcic
- Carlsberg Laboratory, Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Andreas Blennow
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
- * E-mail:
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24
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Wilkens C, Cockburn D, Andersen S, Ole Petersen B, Ruzanski C, A. Field R, Hindsgaul O, Nakai H, McCleary B, M. Smith A, Abou Hachem M, Svensson B. Analysis of Surface Binding Sites (SBS) within GH62, GH13, and GH77. J Appl Glycosci (1999) 2015. [DOI: 10.5458/jag.jag.jag-2015_006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- Casper Wilkens
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark
| | - Darrell Cockburn
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark
| | - Susan Andersen
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark
| | - Bent Ole Petersen
- Carbohydrate Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10
| | | | | | - Ole Hindsgaul
- Carbohydrate Chemistry Group, Carlsberg Laboratory, Gamle Carlsberg Vej 10
| | - Hiroyuki Nakai
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark
| | | | | | - Maher Abou Hachem
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark
| | - Birte Svensson
- Enzyme and Protein Chemistry, Department of Systems Biology, Technical University of Denmark
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25
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Liu H, Yu G, Wei B, Wang Y, Zhang J, Hu Y, Liu Y, Yu G, Zhang H, Huang Y. Identification and Phylogenetic Analysis of a Novel Starch Synthase in Maize. FRONTIERS IN PLANT SCIENCE 2015; 6:1013. [PMID: 26635839 PMCID: PMC4653816 DOI: 10.3389/fpls.2015.01013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 11/02/2015] [Indexed: 05/02/2023]
Abstract
Starch is an important reserve of carbon and energy in plants, providing the majority of calories in the human diet and animal feed. Its synthesis is orchestrated by several key enzymes, and the amount and structure of starch, affecting crop yield and quality, are determined mainly by starch synthase (SS) activity. To date, five SS isoforms, including SSI-IV and Granule Bound Starch Synthase (GBSS) have been identified and their physiological functions have been well characterized. Here, we report the identification of a new SS isoform in maize, designated SSV. By searching sequenced genomes, SSV has been found in all green plants with conserved sequences and gene structures. Our phylogenetic analysis based on 780 base pairs has suggested that SSIV and SSV resulted from a gene duplication event, which may have occurred before the algae formation. An expression profile analysis of SSV in maize has indicated that ZmSSV is mainly transcribed in the kernel and ear leaf during the grain filling stage, which is partly similar to other SS isoforms. Therefore, it is likely that SSV may play an important role in starch biosynthesis. Subsequent analysis of SSV function may facilitate understanding the mechanism of starch granules formation, number and structure.
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Affiliation(s)
- Hanmei Liu
- College of Life Science, Sichuan Agricultural UniversityYa’an, China
| | - Guiling Yu
- College of Life Science, Sichuan Agricultural UniversityYa’an, China
| | - Bin Wei
- Maize Research Institute, Sichuan Agricultural UniversityChengdu, China
| | - Yongbin Wang
- Maize Research Institute, Sichuan Agricultural UniversityChengdu, China
| | - Junjie Zhang
- College of Life Science, Sichuan Agricultural UniversityYa’an, China
| | - Yufeng Hu
- College of Agronomy, Sichuan Agricultural UniversityChengdu, China
| | - Yinghong Liu
- Maize Research Institute, Sichuan Agricultural UniversityChengdu, China
| | - Guowu Yu
- College of Agronomy, Sichuan Agricultural UniversityChengdu, China
| | - Huaiyu Zhang
- College of Life Science, Sichuan Agricultural UniversityYa’an, China
| | - Yubi Huang
- Maize Research Institute, Sichuan Agricultural UniversityChengdu, China
- College of Agronomy, Sichuan Agricultural UniversityChengdu, China
- *Correspondence: Yubi Huang,
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Liang DM, Liu JH, Wu H, Wang BB, Zhu HJ, Qiao JJ. Glycosyltransferases: mechanisms and applications in natural product development. Chem Soc Rev 2015; 44:8350-74. [DOI: 10.1039/c5cs00600g] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glycosylation reactions mainly catalyzed by glycosyltransferases (Gts) occur almost everywhere in the biosphere, and always play crucial roles in vital processes.
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Affiliation(s)
- Dong-Mei Liang
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Jia-Heng Liu
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Hao Wu
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Bin-Bin Wang
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Hong-Ji Zhu
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
| | - Jian-Jun Qiao
- Department of Pharmaceutical Engineering
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin 300072
- China
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Sparla F, Falini G, Botticella E, Pirone C, Talamè V, Bovina R, Salvi S, Tuberosa R, Sestili F, Trost P. New starch phenotypes produced by TILLING in barley. PLoS One 2014; 9:e107779. [PMID: 25271438 PMCID: PMC4182681 DOI: 10.1371/journal.pone.0107779] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 08/15/2014] [Indexed: 01/08/2023] Open
Abstract
Barley grain starch is formed by amylose and amylopectin in a 1∶3 ratio, and is packed into granules of different dimensions. The distribution of granule dimension is bimodal, with a majority of small spherical B-granules and a smaller amount of large discoidal A-granules containing the majority of the starch. Starch granules are semi-crystalline structures with characteristic X-ray diffraction patterns. Distinct features of starch granules are controlled by different enzymes and are relevant for nutritional value or industrial applications. Here, the Targeting-Induced Local Lesions IN Genomes (TILLING) approach was applied on the barley TILLMore TILLING population to identify 29 new alleles in five genes related to starch metabolism known to be expressed in the endosperm during grain filling: BMY1 (Beta-amylase 1), GBSSI (Granule Bound Starch Synthase I), LDA1 (Limit Dextrinase 1), SSI (Starch Synthase I), SSIIa (Starch Synthase IIa). Reserve starch of nine M3 mutant lines carrying missense or nonsense mutations was analysed for granule size, crystallinity and amylose/amylopectin content. Seven mutant lines presented starches with different features in respect to the wild-type: (i) a mutant line with a missense mutation in GBSSI showed a 4-fold reduced amylose/amylopectin ratio; (ii) a missense mutations in SSI resulted in 2-fold increase in A:B granule ratio; (iii) a nonsense mutation in SSIIa was associated with shrunken seeds with a 2-fold increased amylose/amylopectin ratio and different type of crystal packing in the granule; (iv) the remaining four missense mutations suggested a role of LDA1 in granule initiation, and of SSIIa in determining the size of A-granules. We demonstrate the feasibility of the TILLING approach to identify new alleles in genes related to starch metabolism in barley. Based on their novel physicochemical properties, some of the identified new mutations may have nutritional and/or industrial applications.
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Affiliation(s)
- Francesca Sparla
- Department of Pharmacy and Biotechnology FABIT, University of Bologna, Bologna, Italy
| | - Giuseppe Falini
- Department of Chemistry “G. Ciamician”, University of Bologna, Bologna, Italy
| | - Ermelinda Botticella
- Department of Agriculture, Forestry, Nature & Energy, University of Tuscia, Viterbo, Italy
| | - Claudia Pirone
- Department of Pharmacy and Biotechnology FABIT, University of Bologna, Bologna, Italy
| | - Valentina Talamè
- Department of Agricultural Sciences, University of Bologna, Bologna, Italy
| | - Riccardo Bovina
- Department of Agricultural Sciences, University of Bologna, Bologna, Italy
| | - Silvio Salvi
- Department of Agricultural Sciences, University of Bologna, Bologna, Italy
| | - Roberto Tuberosa
- Department of Agricultural Sciences, University of Bologna, Bologna, Italy
| | - Francesco Sestili
- Department of Agriculture, Forestry, Nature & Energy, University of Tuscia, Viterbo, Italy
| | - Paolo Trost
- Department of Pharmacy and Biotechnology FABIT, University of Bologna, Bologna, Italy
- * E-mail:
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Analysis of surface binding sites (SBSs) in carbohydrate active enzymes with focus on glycoside hydrolase families 13 and 77 — a mini-review. Biologia (Bratisl) 2014. [DOI: 10.2478/s11756-014-0373-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Busi MV, Gomez-Casati DF, Martín M, Barchiesi J, Grisolía MJ, Hedín N, Carrillo JB. Starch Metabolism in Green Plants. POLYSACCHARIDES 2014. [DOI: 10.1007/978-3-319-03751-6_78-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Blennow A, Jensen SL, Shaik SS, Skryhan K, Carciofi M, Holm PB, Hebelstrup KH, Tanackovic V. Future Cereal Starch Bioengineering: Cereal Ancestors Encounter Gene Technology and Designer Enzymes. Cereal Chem 2013. [DOI: 10.1094/cchem-01-13-0010-fi] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Andreas Blennow
- Department of Plant and Environmental Sciences, University of Copenhagen, Denmark
- Corresponding author. Phone: +45 35333304. Fax: +45 35333333. E-mail:
| | - Susanne L. Jensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Denmark
| | - Shahnoor S. Shaik
- Department of Plant and Environmental Sciences, University of Copenhagen, Denmark
| | - Katsiaryna Skryhan
- Department of Plant and Environmental Sciences, University of Copenhagen, Denmark
| | - Massimiliano Carciofi
- Department of Molecular Biology and Genetics, Section of Crop Genetics and Biotechnology, Aarhus University, Denmark
| | - Preben B. Holm
- Department of Molecular Biology and Genetics, Section of Crop Genetics and Biotechnology, Aarhus University, Denmark
| | - Kim H. Hebelstrup
- Department of Molecular Biology and Genetics, Section of Crop Genetics and Biotechnology, Aarhus University, Denmark
| | - Vanja Tanackovic
- Department of Plant and Environmental Sciences, University of Copenhagen, Denmark
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