Crystal structures of glycinamide ribonucleotide synthetase, PurD, from thermophilic eubacteria
Sampei, G., Baba, S., Kanagawa, M., Yanai, H., Ishii, T., Kawai, H., Fukai, Y., Ebihara, A., Nakagawa, N., Kawai, G.(2010) J Biochem 148: 429-438
- PubMed: 20716513 
- DOI: https://doi.org/10.1093/jb/mvq088
- Primary Citation of Related Structures:  
2IP4, 2YRW, 2YRX, 2YS6, 2YS7, 2YW2, 2YYA - PubMed Abstract: 
Glycinamide ribonucleotide synthetase (GAR-syn, PurD) catalyses the second reaction of the purine biosynthetic pathway; the conversion of phosphoribosylamine, glycine and ATP to glycinamide ribonucleotide (GAR), ADP and Pi. In the present study, crystal structures of GAR-syn's from Thermus thermophilus, Geobacillus kaustophilus and Aquifex aeolicus were determined in apo forms. Crystal structures in ligand-bound forms were also determined for G. kaustophilus and A. aeolicus proteins. In general, overall structures of GAR-syn's are similar to each other. However, the orientations of the B domains are varied among GAR-syn's and the MD simulation suggested the mobility of the B domain. Furthermore, it was demonstrated that the B loop in the B domain fixes the position of the β- and γ- phosphate groups of the bound ATP. The structures of GAR-syn's and the bound ligands were compared with each other in detail, and structures of GAR-syn's with full ligands, as well as the possible reaction mechanism, were proposed.
Organizational Affiliation: 
Department of Applied Physics and Chemistry, Faculty of Electro-Communications, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu-shi, Tokyo, Japan. sampei@pc.uec.ac.jp