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Title: Crystal structure of glutamate-1-semialdehyde-2,1-aminomutase from Arabidopsis thaliana

A structural study of A. thaliana glutamate-1-semialdehyde-2,1-aminomutase (GSAM) has revealed asymmetry in cofactor binding as well as in the gating-loop orientation, which supports the previously proposed negative cooperativity between monomers of GSAM. Glutamate-1-semialdehyde-2,1-aminomutase (GSAM) catalyzes the isomerization of glutamate-1-semialdehyde (GSA) to 5-aminolevulinate (ALA) and is distributed in archaea, most bacteria and plants. Although structures of GSAM from archaea and bacteria have been resolved, a GSAM structure from a higher plant is not available, preventing further structure–function analysis. Here, the structure of GSAM from Arabidopsis thaliana (AtGSA1) obtained by X-ray crystallography is reported at 1.25 Å resolution. AtGSA1 forms an asymmetric dimer and displays asymmetry in cofactor binding as well as in the gating-loop orientation, which is consistent with previously reported Synechococcus GSAM structures. While one monomer binds PMP with the gating loop fixed in the open state, the other monomer binds either PMP or PLP and the gating loop is ready to close. The data also reveal the mobility of residues Gly163, Ser164 and Gly165, which are important for reorientation of the gating loop. Furthermore, the asymmetry of the AtGSA1 structure supports the previously proposed negative cooperativity between monomers of GSAM.
Authors:
; ; ; ;  [1]
  1. Chinese Academy of Sciences, Beijing 100093, People’s Republic of (China)
Publication Date:
OSTI Identifier:
22516330
Resource Type:
Journal Article
Resource Relation:
Journal Name: Acta Crystallographica. Section F, Structural Biology Communications; Journal Volume: 72; Journal Issue: Pt 6; Other Information: PMCID: PMC4909244; PMID: 27303897; PUBLISHER-ID: us5093; PUBLISHER-ID: S2053230X16007263; OAI: oai:pubmedcentral.nih.gov:4909244; Copyright (c) Song et al. 2016; This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ASYMMETRY; CRYSTAL STRUCTURE; MONOMERS; PHOSPHATES; X RADIATION