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Foresi N, De Marco MA, Del Castello F, Ramirez L, Nejamkin A, Calo G, Grimsley N, Correa-Aragunde N, Martínez-Noël GMA. The tiny giant of the sea, Ostreococcus's unique adaptations. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 211:108661. [PMID: 38735153 DOI: 10.1016/j.plaphy.2024.108661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 04/14/2024] [Accepted: 04/23/2024] [Indexed: 05/14/2024]
Abstract
Ostreococcus spp. are unicellular organisms with one of the simplest cellular organizations. The sequencing of the genomes of different Ostreococcus species has reinforced this status since Ostreococcus tauri has one most compact nuclear genomes among eukaryotic organisms. Despite this, it has retained a number of genes, setting it apart from other organisms with similar small genomes. Ostreococcus spp. feature a substantial number of selenocysteine-containing proteins, which, due to their higher catalytic activity compared to their selenium-lacking counterparts, may require a reduced quantity of proteins. Notably, O. tauri encodes several ammonium transporter genes, that may provide it with a competitive edge for acquiring nitrogen (N). This characteristic makes it an intriguing model for studying the efficient use of N in eukaryotes. Under conditions of low N availability, O. tauri utilizes N from abundant proteins or amino acids, such as L-arginine, similar to higher plants. However, the presence of a nitric oxide synthase (L-arg substrate) sheds light on a new metabolic pathway for L-arg in algae. The metabolic adaptations of O. tauri to day and night cycles offer valuable insights into carbon and iron metabolic configuration. O. tauri has evolved novel strategies to optimize iron uptake, lacking the classic components of the iron absorption mechanism. Overall, the cellular and genetic characteristics of Ostreococcus contribute to its evolutionary success, making it an excellent model for studying the physiological and genetic aspects of how green algae have adapted to the marine environment. Furthermore, given its potential for lipid accumulation and its marine habitat, it may represent a promising avenue for third-generation biofuels.
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Affiliation(s)
- Noelia Foresi
- Instituto de Investigaciones Biológicas-UNMdP-CONICET, Mar del Plata, Argentina.
| | - María Agustina De Marco
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC)-CONICET-FIBA, Mar del Plata, Argentina
| | | | - Leonor Ramirez
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, SE-901 87, Umeå, Sweden
| | - Andres Nejamkin
- Instituto de Investigaciones Biológicas-UNMdP-CONICET, Mar del Plata, Argentina
| | - Gonzalo Calo
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC)-CONICET-FIBA, Mar del Plata, Argentina
| | - Nigel Grimsley
- CNRS, LBBM, Sorbonne Université OOB, 1 Avenue de Pierre Fabre, 66650, Banyuls-sur-Mer, France
| | | | - Giselle M A Martínez-Noël
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC)-CONICET-FIBA, Mar del Plata, Argentina.
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Cabral VÁ, Govoni B, Verli H. Unravelling carbohydrate binding module 21 (CBM21) dynamics of interaction with amylose. Carbohydr Polym 2024; 330:121792. [PMID: 38368081 DOI: 10.1016/j.carbpol.2024.121792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/21/2023] [Accepted: 01/05/2024] [Indexed: 02/19/2024]
Abstract
The carbohydrate binding module 21 (CBM21) from Rhizopus oryzae is a dual-site CBM proposed to disrupt polysaccharide structures. Additionally, it serves as a purification tag in industry. CBM21 crystal structure features a Glc residue in an unusual 1S3 conformation, whose relevance for the CBM mechanism of action is unclear. In this context, we seek to contribute for the understanding of CBM21 mechanism of action by: i) investigating the role of the 1S3 conformation on carbohydrate recognition, and ii) characterize the protein-carbohydrate binding dynamics using molecular dynamics and metadynamics simulations at MM and QM/MM levels. Results indicate the 1S3 Glc conformation is unlikely to occur under biological conditions, being originated from the crystallographic environment. CBM21 binding to small ligands appears transient and unstable, while protein dimerization and polysaccharide chain size influence complex stability. In interactions with amylose, CBM21 exhibits a repeated unbinding followed by re-binding, while simultaneously alternating between binding sites I and II. These results suggest that CBM21 acts through transient interactions, directing carbohydrates to the catalytic center rather than forming strong and long-lasting bonds with carbohydrates. Accordingly, we expect such atomistic depiction of CBM21 mechanism could aid in CBM design targeting biotechnological applications.
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Affiliation(s)
- Vinicius Ávila Cabral
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre 91500-970, RS, Brazil
| | - Bruna Govoni
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre 91500-970, RS, Brazil
| | - Hugo Verli
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500, Porto Alegre 91500-970, RS, Brazil.
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3
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Prabhakar PK, Pereira JH, Taujale R, Shao W, Bharadwaj VS, Chapla D, Yang JY, Bomble YJ, Moremen KW, Kannan N, Hammel M, Adams PD, Scheller HV, Urbanowicz BR. Structural and biochemical insight into a modular β-1,4-galactan synthase in plants. NATURE PLANTS 2023; 9:486-500. [PMID: 36849618 PMCID: PMC10115243 DOI: 10.1038/s41477-023-01358-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 01/25/2023] [Indexed: 05/18/2023]
Abstract
Rhamnogalacturonan I (RGI) is a structurally complex pectic polysaccharide with a backbone of alternating rhamnose and galacturonic acid residues substituted with arabinan and galactan side chains. Galactan synthase 1 (GalS1) transfers galactose and arabinose to either extend or cap the β-1,4-galactan side chains of RGI, respectively. Here we report the structure of GalS1 from Populus trichocarpa, showing a modular protein consisting of an N-terminal domain that represents the founding member of a new family of carbohydrate-binding module, CBM95, and a C-terminal glycosyltransferase family 92 (GT92) catalytic domain that adopts a GT-A fold. GalS1 exists as a dimer in vitro, with stem domains interacting across the chains in a 'handshake' orientation that is essential for maintaining stability and activity. In addition to understanding the enzymatic mechanism of GalS1, we gained insight into the donor and acceptor substrate binding sites using deep evolutionary analysis, molecular simulations and biochemical studies. Combining all the results, a mechanism for GalS1 catalysis and a new model for pectic galactan side-chain addition are proposed.
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Affiliation(s)
- Pradeep Kumar Prabhakar
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oakridge, TN, USA
| | - Jose Henrique Pereira
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Rahil Taujale
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Wanchen Shao
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Vivek S Bharadwaj
- Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Digantkumar Chapla
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Jeong-Yeh Yang
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Yannick J Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Kelley W Moremen
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Natarajan Kannan
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Paul D Adams
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Henrik V Scheller
- Joint BioEnergy Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Breeanna R Urbanowicz
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA.
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oakridge, TN, USA.
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Chen L, Du M, Wang L, Yu W, Chen Y, Cheng B, Wu J. Maize STARCH SYNTHESIS REGULATING PROTEIN1 positively regulates starch biosynthesis in rice endosperm. FUNCTIONAL PLANT BIOLOGY : FPB 2022; 49:773-783. [PMID: 35491402 DOI: 10.1071/fp21338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 04/09/2022] [Indexed: 06/14/2023]
Abstract
Starch is a major component of the endosperm, directly determining grain yield and quality. Although the key enzymes of starch synthesis have been identified and characterised, the regulatory mechanisms remain unclear. In this study, we identified the novel maize STARCH SYNTHESIS REGULATING PROTEIN1 (ZmSSRP1 ), which encodes a typical carbohydrate-binding module 48 (CBM48) protein. Expression analysis revealed that ZmSSRP1 was highly expressed in the maize endosperm, while transient expression in maize leaf protoplasts showed localisation in the plastids, dependent on the N-terminal transit peptide. In addition, overexpression of ZmSSRP1 in rice resulted in a decrease in grain thickness and the 1000-grain weight, as well as affecting the starch content and structure of the rice endosperm. The physicochemical properties of starch in the rice endosperm were also altered compared with the wild-type seeds. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was subsequently performed to determine the expression of starch synthesis-related genes, revealing upregulation of mRNA expression of most genes in the transgenic compared with wild-type lines. Collectively, these findings suggest that ZmSSRP1 acts as a potential regulator of starch synthesis, providing new insight for molecular breeding of high-yielding high-quality maize.
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Affiliation(s)
- Long Chen
- National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Ming Du
- National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei 230036, Anhui, China; and Shanghai Zhongke Quanyin Molecular Breeding Technology, Shanghai 200030, China
| | - Long Wang
- National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Wei Yu
- National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Yirong Chen
- National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Beijiu Cheng
- National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei 230036, Anhui, China
| | - Jiandong Wu
- National Engineering Laboratory of Crop Stress Resistance, College of Life Science, Anhui Agricultural University, Hefei 230036, Anhui, China
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Functional Characterization of Recombinant Raw Starch Degrading α-Amylase from Roseateles terrae HL11 and Its Application on Cassava Pulp Saccharification. Catalysts 2022. [DOI: 10.3390/catal12060647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Exploring new raw starch-hydrolyzing α-amylases and understanding their biochemical characteristics are important for the utilization of starch-rich materials in bio-industry. In this work, the biochemical characteristics of a novel raw starch-degrading α-amylase (HL11 Amy) from Roseateles terrae HL11 was firstly reported. Evolutionary analysis revealed that HL11Amy was classified into glycoside hydrolase family 13 subfamily 32 (GH13_32). It contains four protein domains consisting of domain A, domain B, domain C and carbohydrate-binding module 20 (CMB20). The enzyme optimally worked at 50 °C, pH 4.0 with a specific activity of 6270 U/mg protein and 1030 raw starch-degrading (RSD) U/mg protein against soluble starch. Remarkably, HL11Amy exhibited activity toward both raw and gelatinized forms of various substrates, with the highest catalytic efficiency (kcat/Km) on starch from rice, followed by potato and cassava, respectively. HL11Amy effectively hydrolyzed cassava pulp (CP) hydrolysis, with a reducing sugar yield of 736 and 183 mg/g starch from gelatinized and raw CP, equivalent to 72% and 18% conversion based on starch content in the substrate, respectively. These demonstrated that HL11Amy represents a promising raw starch-degrading enzyme with potential applications in starch modification and cassava pulp saccharification.
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