부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jmb.2005.05.064 Byline: Yutaka Oda, Koshiki Mino, Kazuhiko Ishikawa, Mitsuo Ataka Abstract: O-Phosphoserine sulfhydrylase is a new enzyme found in a hyperthermophilic archaeon, Aeropyrum pernix K1. This enzyme catalyzes a novel cysteine synthetic reaction from O-phospho-l-serine and sulfide. The crystal structure of the enzyme was determined at 2.0a' resolution using the method of multi-wavelength anomalous dispersion. A monomer consists of three domains, including an N-terminal domain with a new [alpha]/[beta] fold. The topology folds of the middle and C-terminal domains were similar to those of the O-acetylserine sulfhydrylase-A from Salmonella typhimurium and the cystathionine [beta]-synthase from human. The cofactor, pyridoxal 5'-phosphate, is bound in a cleft between the middle and C-terminal domains through a covalent linkage to Lys127. Based on the structure determined, O-phospho-l-serine could be rationally modeled into the active site of the enzyme. An enzyme-substrate complex model and a mutation experiment revealed that Arg297, unique to hyperthermophilic archaea, is one of the most crucial residues for O-phosphoserine sulfhydrylation activity. There are more hydrophobic areas and less electric charges at the dimer interface, compared to the S.typhimurium O-acetylserine sulfhydrylase. Author Affiliation: Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology (AIST, Kansai), 1-8-31, Midorigaoka, Ikeda, Osaka 563-8577, Japan Article History: Received 24 February 2005; Revised 18 May 2005; Accepted 26 May 2005 Article Note: (miscellaneous) Edited by K. Morikawa