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Huang A, Coutu C, Harrington M, Rozwadowski K, Hegedus DD. Engineering a feedback inhibition-insensitive plant dihydrodipicolinate synthase to increase lysine content in Camelina sativa seeds. Transgenic Res 2021; 31:131-148. [PMID: 34802109 PMCID: PMC8821502 DOI: 10.1007/s11248-021-00291-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 11/11/2021] [Indexed: 11/28/2022]
Abstract
Camelina sativa (camelina) is emerging as an alternative oilseed crop due to its short growing cycle, low input requirements, adaptability to less favorable growing environments and a seed oil profile suitable for biofuel and industrial applications. Camelina meal and oil are also registered for use in animal and fish feeds; however, like meals derived from most cereals and oilseeds, it is deficient in certain essential amino acids, such as lysine. In higher plants, the reaction catalyzed by dihydrodipicolinate synthase (DHDPS) is the first committed step in the biosynthesis of lysine and is subject to regulation by lysine through feedback inhibition. Here, we report enhancement of lysine content in C. sativa seed via expression of a feedback inhibition-insensitive form of DHDPS from Corynebacterium glutamicums (CgDHDPS). Two genes encoding C. sativa DHDPS were identified and the endogenous enzyme is partially insensitive to lysine inhibition. Site-directed mutagenesis was used to examine the impact of alterations, alone and in combination, present in lysine-desensitized DHDPS isoforms from Arabidopsis thaliana DHDPS (W53R), Nicotiana tabacum (N80I) and Zea mays (E84K) on C. sativa DHDPS lysine sensitivity. When introduced alone, each of the alterations decreased sensitivity to lysine; however, enzyme specific activity was also affected. There was evidence of molecular or structural interplay between residues within the C. sativa DHDPS allosteric site as coupling of the W53R mutation with the N80V mutation decreased lysine sensitivity of the latter, but not to the level with the W53R mutation alone. Furthermore, the activity and lysine sensitivity of the triple mutant (W53R/N80V/E84T) was similar to the W53R mutation alone or the C. glutamicum DHDPS. The most active and most lysine-insensitive C. sativa DHDPS variant (W53R) was not inhibited by free lysine up to 1 mM, comparable to the C. glutamicums enzyme. Seed lysine content increased 13.6 -22.6% in CgDHDPS transgenic lines and 7.6–13.2% in the mCsDHDPS lines. The high lysine-accumulating lines from this work may be used to produce superior quality animal feed with improved essential amino acid profile.
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Affiliation(s)
- Alex Huang
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Cathy Coutu
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Myrtle Harrington
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Kevin Rozwadowski
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Dwayne D Hegedus
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada. .,Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada.
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Impey RE, Panjikar S, Hall CJ, Bock LJ, Sutton JM, Perugini MA, Soares da Costa TP. Identification of two dihydrodipicolinate synthase isoforms from Pseudomonas aeruginosa that differ in allosteric regulation. FEBS J 2019; 287:386-400. [PMID: 31330085 DOI: 10.1111/febs.15014] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 06/12/2019] [Accepted: 07/19/2019] [Indexed: 12/13/2022]
Abstract
Pseudomonas aeruginosa is one of the leading causes of nosocomial infections, accounting for 10% of all hospital-acquired infections. Current antibiotics against P. aeruginosa are becoming increasingly ineffective due to the exponential rise in drug resistance. Thus, there is an urgent need to validate and characterize novel drug targets to guide the development of new classes of antibiotics against this pathogen. One such target is the diaminopimelate (DAP) pathway, which is responsible for the biosynthesis of bacterial cell wall and protein building blocks, namely meso-DAP and lysine. The rate-limiting step of this pathway is catalysed by the enzyme dihydrodipicolinate synthase (DHDPS), typically encoded for in bacteria by a single dapA gene. Here, we show that P. aeruginosa encodes two functional DHDPS enzymes, PaDHDPS1 and PaDHDPS2. Although these isoforms have similar catalytic activities (kcat = 29 s-1 and 44 s-1 for PaDHDPS1 and PaDHDPS2, respectively), they are differentially allosterically regulated by lysine, with only PaDHDPS2 showing inhibition by the end product of the DAP pathway (IC50 = 130 μm). The differences in allostery are attributed to a single amino acid difference in the allosteric binding pocket at position 56. This is the first example of a bacterium that contains multiple bona fide DHDPS enzymes, which differ in allosteric regulation. We speculate that the presence of the two isoforms allows an increase in the metabolic flux through the DAP pathway when required in this clinically important pathogen. DATABASES: PDB ID: 6P90.
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Affiliation(s)
- Rachael E Impey
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Santosh Panjikar
- Australian Synchrotron, ANSTO, Clayton, Australia.,Department of Molecular Biology and Biochemistry, Monash University, Melbourne, Australia
| | - Cody J Hall
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Lucy J Bock
- National Infection Service, Public Health England, Porton Down, Salisbury, UK
| | - J Mark Sutton
- National Infection Service, Public Health England, Porton Down, Salisbury, UK
| | - Matthew A Perugini
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
| | - Tatiana P Soares da Costa
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Australia
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Desbois S, John UP, Perugini MA. Dihydrodipicolinate synthase is absent in fungi. Biochimie 2018; 152:73-84. [PMID: 29959064 DOI: 10.1016/j.biochi.2018.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 06/21/2018] [Indexed: 02/07/2023]
Abstract
The class I aldolase dihydrodipicolinate synthase (DHDPS) catalyzes the first committed step of the diaminopimelate (DAP) lysine biosynthesis pathway in bacteria, archaea and plants. Despite the existence, in databases, of numerous fungal sequences annotated as DHDPS, its presence in fungi has been the subject of contradictory claims. We report the characterization of DHDPS candidates from fungi. Firstly, the putative DHDPS from Coccidioides immitis (PDB ID: 3QFE) was shown to have negligible enzyme activity. Sequence analysis of 3QFE showed that three out of the seven amino acid residues critical for DHDPS activity are absent; however, exact matches to catalytic residues from two other class I aldolases, 2-keto-3-deoxygluconate aldolase (KDGA), and 4-hydroxy-2-oxoglutarate aldolase (HOGA), were identified. The presence of both KDGA and HOGA activity in 3QFE was confirmed in vitro using enzyme assays, the first report of such dual activity. Subsequent analyses of all publically available fungal sequences revealed that no entry contains all seven residues important for DHDPS function. The candidate with the highest number of identities (6 of 7), KIW77228 from Fonsecaea pedrosoi, was shown to have trace DHDPS activity in vitro, partially restored by substitution of the seventh critical residue, and to be incapable of complementing DHDPS-deficient E. coli cells. Combined with the presence of all seven sequences for the alternative α-aminoadipate (AAA) lysine biosynthesis pathway in C. immitis and F. pedrosoi, we believe that DHDPS and the DAP pathway are absent in fungi, and further, that robust informed methods for annotating genes need to be implemented.
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Affiliation(s)
- Sebastien Desbois
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, VIC, 3086, Australia
| | - Ulrik P John
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, VIC, 3086, Australia; Agriculture Victoria Research, Department of Economic Development, Jobs, Transport and Resources, AgriBio, La Trobe University, VIC, 3086, Australia
| | - Matthew A Perugini
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, VIC, 3086, Australia.
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Soares da Costa TP, Abbott BM, Gendall AR, Panjikar S, Perugini MA. Molecular evolution of an oligomeric biocatalyst functioning in lysine biosynthesis. Biophys Rev 2018; 10:153-162. [PMID: 29204887 PMCID: PMC5899710 DOI: 10.1007/s12551-017-0350-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 11/14/2017] [Indexed: 12/28/2022] Open
Abstract
Dihydrodipicolinate synthase (DHDPS) is critical to the production of lysine through the diaminopimelate (DAP) pathway. Elucidation of the function, regulation and structure of this key class I aldolase has been the focus of considerable study in recent years, given that the dapA gene encoding DHDPS has been found to be essential to bacteria and plants. Allosteric inhibition by lysine is observed for DHDPS from plants and some bacterial species, the latter requiring a histidine or glutamate at position 56 (Escherichia coli numbering) over a basic amino acid. Structurally, two DHDPS monomers form the active site, which binds pyruvate and (S)-aspartate β-semialdehyde, with most dimers further dimerising to form a tetrameric arrangement around a solvent-filled centre cavity. The architecture and behaviour of these dimer-of-dimers is explored in detail, including biophysical studies utilising analytical ultracentrifugation, small-angle X-ray scattering and macromolecular crystallography that show bacterial DHDPS tetramers adopt a head-to-head quaternary structure, compared to the back-to-back arrangement observed for plant DHDPS enzymes. Finally, the potential role of pyruvate in providing substrate-mediated stabilisation of DHDPS is considered.
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Affiliation(s)
- Tatiana P Soares da Costa
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Belinda M Abbott
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Anthony R Gendall
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, La Trobe University, Bundoora, VIC, 3086, Australia
| | - Santosh Panjikar
- Australian Synchrotron, Clayton, Melbourne, VIC, 3168, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Melbourne, VIC, 3800, Australia
| | - Matthew A Perugini
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
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Soares da Costa TP, Patel M, Desbois S, Gupta R, Faou P, Perugini MA. Identification of a dimeric KDG aldolase from
Agrobacterium tumefaciens. Proteins 2017; 85:2058-2065. [DOI: 10.1002/prot.25359] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 07/17/2017] [Accepted: 07/24/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Tatiana P. Soares da Costa
- Department of Biochemistry and GeneticsLa Trobe Institute for Molecular Science, La Trobe UniversityMelbourne Victoria Australia
| | - Madhvi Patel
- Department of Biochemistry and GeneticsLa Trobe Institute for Molecular Science, La Trobe UniversityMelbourne Victoria Australia
| | - Sebastien Desbois
- Department of Biochemistry and GeneticsLa Trobe Institute for Molecular Science, La Trobe UniversityMelbourne Victoria Australia
| | - Ruchi Gupta
- Department of Biochemistry and GeneticsLa Trobe Institute for Molecular Science, La Trobe UniversityMelbourne Victoria Australia
| | - Pierre Faou
- Department of Biochemistry and GeneticsLa Trobe Institute for Molecular Science, La Trobe UniversityMelbourne Victoria Australia
| | - Matthew A. Perugini
- Department of Biochemistry and GeneticsLa Trobe Institute for Molecular Science, La Trobe UniversityMelbourne Victoria Australia
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Crystal structure and in silico studies of dihydrodipicolinate synthase (DHDPS) from Aquifex aeolicus. Extremophiles 2014; 18:973-85. [PMID: 24996798 DOI: 10.1007/s00792-014-0667-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 06/07/2014] [Indexed: 10/25/2022]
Abstract
Dihydrodipicolinate synthase (DHDPS, E.C.4.2.1.52) catalyzes the first committed step in the lysine biosynthetic pathway: the condensation of (S)-aspartate semialdehyde and pyruvate to form (4S)-4-hydroxy-2,3,4,5-tetrahydro-(2S)-dipicolinic acid. Since (S)-lysine biosynthesis does not occur in animals, DHDPS is an attractive target for rational antibiotic and herbicide design. Here, we report the crystal structure of DHDPS from a hyperthermophilic bacterium Aquifex aeolicus (AqDHDPS). L-Lysine is used as an important animal feed additive where the production is at the level of 1.5 million tons per year. The biotechnological manufacture of lysine has been going for more than 50 years which includes over synthesis and reverse engineering of DHDPS. AqDHDPS revealed a unique disulfide linkage which is not conserved in the homologues of AqDHDPS. In silico mutation of C139A and intermolecular ion-pair residues and the subsequent molecular dynamics simulation of the mutants showed that these residues are critical for the stability of AqDHDPS tetramer. MD simulations of AqDHDPS at three different temperatures (303, 363 and 393 K) revealed that the molecule is stable at 363 K. Thus, this structural and in silico study of AqDHDPS likely provides additional details towards the rational and structure-based design of hyper-L-lysine producing bacterial strains.
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Atkinson SC, Hor L, Dogovski C, Dobson RCJ, Perugini MA. Identification of the bona fide DHDPS from a common plant pathogen. Proteins 2014; 82:1869-83. [PMID: 24677246 DOI: 10.1002/prot.24539] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 01/06/2014] [Accepted: 02/13/2014] [Indexed: 11/10/2022]
Abstract
Agrobacterium tumefaciens is a Gram-negative soil-borne bacterium that causes Crown Gall disease in many economically important crops. The absence of a suitable chemical treatment means there is a need to discover new anti-Crown Gall agents and also characterize bona fide drug targets. One such target is dihydrodipicolinate synthase (DHDPS), a homo-tetrameric enzyme that catalyzes the committed step in the metabolic pathway yielding meso-diaminopimelate and lysine. Interestingly, there are 10 putative DHDPS genes annotated in the A. tumefaciens genome, including three whose structures have recently been determined (PDB IDs: 3B4U, 2HMC, and 2R8W). However, we show using quantitative enzyme kinetic assays that nine of the 10 dapA gene products, including 3B4U, 2HMC, and 2R8W, lack DHDPS function in vitro. A sequence alignment showed that the product of the dapA7 gene contains all of the conserved residues known to be important for DHDPS catalysis and allostery. This gene was cloned and the recombinant product expressed and purified. Our studies show that the purified enzyme (i) possesses DHDPS enzyme activity, (ii) is allosterically inhibited by lysine, and (iii) adopts the canonical homo-tetrameric structure in both solution and the crystal state. This study describes for the first time the structure, function and allostery of the bona fide DHDPS from A. tumefaciens, which offers insight into the rational design of pesticide agents for combating Crown Gall disease.
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Affiliation(s)
- Sarah C Atkinson
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, 3086, Australia; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
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Siddiqui T, Paxman JJ, Dogovski C, Panjikar S, Perugini MA. Cloning to crystallization of dihydrodipicolinate synthase from the intracellular pathogen Legionella pneumophila. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:1177-81. [PMID: 24100576 PMCID: PMC3792684 DOI: 10.1107/s1744309113024639] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Accepted: 09/03/2013] [Indexed: 11/11/2022]
Abstract
Dihydrodipicolinate synthase (DHDPS) catalyses the rate-limiting step in the biosynthesis of meso-diaminopimelate and lysine. Here, the cloning, expression, purification and crystallization of DHDPS from the intracellular pathogen Legionella pneumophila are described. Crystals grown in the presence of high-molecular-weight PEG precipitant and magnesium chloride were found to diffract beyond 1.65 Å resolution. The crystal lattice belonged to the hexagonal space group P6₁22, with unit-cell parameters a=b=89.31, c=290.18 Å, and contained two molecules in the asymmetric unit. The crystal structure was determined by molecular replacement using a single chain of Pseudomonas aeruginosa DHDPS as the search model.
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Affiliation(s)
- Tanzeela Siddiqui
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, VIC 3010, Australia
| | | | - Con Dogovski
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, VIC 3010, Australia
| | - Santosh Panjikar
- Australian Synchrotron, Clayton, VIC 3168, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Melbourne, VIC 3800, Australia
| | - Matthew A. Perugini
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, VIC 3010, Australia
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