Crystal Structure and Functional Characterization of Acetylornithine Aminotransferase from Corynebacterium glutamicum.
Ki, D., Hong, H., Kim, I.K., Kim, K.J.(2023) J Agric Food Chem 71: 8471-8478
- PubMed: 37230944 
- DOI: https://doi.org/10.1021/acs.jafc.3c00659
- Primary Citation of Related Structures:  
8HT2, 8HT4 - PubMed Abstract: 
The amino acids l-arginine and l-ornithine are widely used in animal feed and as health supplements and pharmaceutical compounds. In arginine biosynthesis, acetylornithine aminotransferase (AcOAT) uses pyridoxal-5'-phosphate (PLP) as a cofactor for amino group transfer. Here, we determined the crystal structures of the apo and PLP complex forms of AcOAT from Corynebacterium glutamicum ( Cg AcOAT). Our structural observations revealed that Cg AcOAT undergoes an order-to-disorder conformational change upon binding with PLP. Additionally, we observed that unlike other AcOATs, Cg AcOAT exists as a tetramer. Subsequently, we identified the key residues involved in PLP and substrate binding based on structural analysis and site-directed mutagenesis. This study might provide structural insights on Cg AcOAT, which can be utilized for the development of improved l-arginine production enzymes.
Organizational Affiliation: 
School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea.