5IWQ

Crystal structure of aspartate aminotransferase (AspAT) from Corynebacterium glutamicum ATCC 13032

Summary for 5IWQ

• Entry DOI: 10.2210/pdb5iwq/pdb
• Descriptor: ASPARTATE AMINOTRANSFERASE, PYRIDOXAL-5'-PHOSPHATE, GLYCEROL, ... (5 entities in total)
• Functional Keywords: aminotransferase, transferase
• Biological source: Corynebacterium glutamicum (strain ATCC 13032 / DSM 20300 / JCM 1318 / LMG 3730 / NCIMB 10025)
• Total number of polymer chains: 2
• Total formula weight: 96877.42

Authors

Son, H.F.,Kim, K.J. (deposition date: 2016-03-22, release date: 2016-07-20, Last modification date: 2023-11-08)

Primary citation

Son, H.F.,Kim, K.J.
Structural Insights into a Novel Class of Aspartate Aminotransferase from Corynebacterium glutamicum.
Plos One, 11:e0158402-e0158402, 2016

PubMed Abstract: Aspartate aminotransferase from Corynebacterium glutamicum (CgAspAT) is a PLP-dependent enzyme that catalyzes the production of L-aspartate and α-ketoglutarate from L-glutamate and oxaloacetate in L-lysine biosynthesis. In order to understand the molecular mechanism of CgAspAT and compare it with those of other aspartate aminotransferases (AspATs) from the aminotransferase class I, we determined the crystal structure of CgAspAT. CgAspAT functions as a dimer, and the CgAspAT monomer consists of two domains, the core domain and the auxiliary domain. The PLP cofactor is found to be bound to CgAspAT and stabilized through unique residues. In our current structure, a citrate molecule is bound at the active site of one molecule and mimics binding of the glutamate substrate. The residues involved in binding of the PLP cofactor and the glutamate substrate were confirmed by site-directed mutagenesis. Interestingly, compared with other AspATs from aminotransferase subgroup Ia and Ib, CgAspAT exhibited unique binding sites for both cofactor and substrate; moreover, it was found to have unusual structural features in the auxiliary domain. Based on these structural differences, we propose that CgAspAT does not belong to either subgroup Ia or Ib, and can be categorized into a subgroup Ic. The phylogenetic tree and RMSD analysis also indicates that CgAspAT is located in an independent AspAT subgroup.

PubMed: 27355211
DOI: 10.1371/journal.pone.0158402

Experimental method

X-RAY DIFFRACTION (2 Å)