Characterisation of the first enzymes committed to lysine biosynthesis in Arabidopsis thaliana.

In plants, the lysine biosynthetic pathway is an attractive target for both the development of herbicides and increasing the nutritional value of crops given that lysine is a limiting amino acid in cereals. Dihydrodipicolinate synthase (DHDPS) and dihydrodipicolinate reductase (DHDPR) catalyse the f...

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Main Authors: Michael D W Griffin, Jagan M Billakanti, Akshita Wason, Sabrina Keller, Haydyn D T Mertens, Sarah C Atkinson, Renwick C J Dobson, Matthew A Perugini, Juliet A Gerrard, Frederick Grant Pearce
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2012-01-01
Series:PLoS ONE
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22792278/?tool=EBI
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author Michael D W Griffin
Jagan M Billakanti
Akshita Wason
Sabrina Keller
Haydyn D T Mertens
Sarah C Atkinson
Renwick C J Dobson
Matthew A Perugini
Juliet A Gerrard
Frederick Grant Pearce
author_facet Michael D W Griffin
Jagan M Billakanti
Akshita Wason
Sabrina Keller
Haydyn D T Mertens
Sarah C Atkinson
Renwick C J Dobson
Matthew A Perugini
Juliet A Gerrard
Frederick Grant Pearce
author_sort Michael D W Griffin
collection DOAJ
description In plants, the lysine biosynthetic pathway is an attractive target for both the development of herbicides and increasing the nutritional value of crops given that lysine is a limiting amino acid in cereals. Dihydrodipicolinate synthase (DHDPS) and dihydrodipicolinate reductase (DHDPR) catalyse the first two committed steps of lysine biosynthesis. Here, we carry out for the first time a comprehensive characterisation of the structure and activity of both DHDPS and DHDPR from Arabidopsis thaliana. The A. thaliana DHDPS enzyme (At-DHDPS2) has similar activity to the bacterial form of the enzyme, but is more strongly allosterically inhibited by (S)-lysine. Structural studies of At-DHDPS2 show (S)-lysine bound at a cleft between two monomers, highlighting the allosteric site; however, unlike previous studies, binding is not accompanied by conformational changes, suggesting that binding may cause changes in protein dynamics rather than large conformation changes. DHDPR from A. thaliana (At-DHDPR2) has similar specificity for both NADH and NADPH during catalysis, and has tighter binding of substrate than has previously been reported. While all known bacterial DHDPR enzymes have a tetrameric structure, analytical ultracentrifugation, and scattering data unequivocally show that At-DHDPR2 exists as a dimer in solution. The exact arrangement of the dimeric protein is as yet unknown, but ab initio modelling of x-ray scattering data is consistent with an elongated structure in solution, which does not correspond to any of the possible dimeric pairings observed in the X-ray crystal structure of DHDPR from other organisms. This increased knowledge of the structure and function of plant lysine biosynthetic enzymes will aid future work aimed at improving primary production.
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spelling doaj.art-1ea922ff58024eaf9855c830510354cf2022-12-21T23:41:09ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0177e4031810.1371/journal.pone.0040318Characterisation of the first enzymes committed to lysine biosynthesis in Arabidopsis thaliana.Michael D W GriffinJagan M BillakantiAkshita WasonSabrina KellerHaydyn D T MertensSarah C AtkinsonRenwick C J DobsonMatthew A PeruginiJuliet A GerrardFrederick Grant PearceIn plants, the lysine biosynthetic pathway is an attractive target for both the development of herbicides and increasing the nutritional value of crops given that lysine is a limiting amino acid in cereals. Dihydrodipicolinate synthase (DHDPS) and dihydrodipicolinate reductase (DHDPR) catalyse the first two committed steps of lysine biosynthesis. Here, we carry out for the first time a comprehensive characterisation of the structure and activity of both DHDPS and DHDPR from Arabidopsis thaliana. The A. thaliana DHDPS enzyme (At-DHDPS2) has similar activity to the bacterial form of the enzyme, but is more strongly allosterically inhibited by (S)-lysine. Structural studies of At-DHDPS2 show (S)-lysine bound at a cleft between two monomers, highlighting the allosteric site; however, unlike previous studies, binding is not accompanied by conformational changes, suggesting that binding may cause changes in protein dynamics rather than large conformation changes. DHDPR from A. thaliana (At-DHDPR2) has similar specificity for both NADH and NADPH during catalysis, and has tighter binding of substrate than has previously been reported. While all known bacterial DHDPR enzymes have a tetrameric structure, analytical ultracentrifugation, and scattering data unequivocally show that At-DHDPR2 exists as a dimer in solution. The exact arrangement of the dimeric protein is as yet unknown, but ab initio modelling of x-ray scattering data is consistent with an elongated structure in solution, which does not correspond to any of the possible dimeric pairings observed in the X-ray crystal structure of DHDPR from other organisms. This increased knowledge of the structure and function of plant lysine biosynthetic enzymes will aid future work aimed at improving primary production.https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22792278/?tool=EBI
spellingShingle Michael D W Griffin
Jagan M Billakanti
Akshita Wason
Sabrina Keller
Haydyn D T Mertens
Sarah C Atkinson
Renwick C J Dobson
Matthew A Perugini
Juliet A Gerrard
Frederick Grant Pearce
Characterisation of the first enzymes committed to lysine biosynthesis in Arabidopsis thaliana.
PLoS ONE
title Characterisation of the first enzymes committed to lysine biosynthesis in Arabidopsis thaliana.
title_full Characterisation of the first enzymes committed to lysine biosynthesis in Arabidopsis thaliana.
title_fullStr Characterisation of the first enzymes committed to lysine biosynthesis in Arabidopsis thaliana.
title_full_unstemmed Characterisation of the first enzymes committed to lysine biosynthesis in Arabidopsis thaliana.
title_short Characterisation of the first enzymes committed to lysine biosynthesis in Arabidopsis thaliana.
title_sort characterisation of the first enzymes committed to lysine biosynthesis in arabidopsis thaliana
url https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/22792278/?tool=EBI
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