Authors: Feng Xie Shengwang Dai Jinzhao Shen Biao Ren Pei Huang Qiushui Wang Xueting Liu Buchang Zhang Huanqin Dai Lixin Zhang
Publish Date: 2015/01/15
Volume: 99, Issue: 14, Pages: 5895-5905
Abstract
Siderophores are important for the growth of bacteria or the applications in treatment of iron overloadassociated diseases due to the ironchelating property Salicylate synthase played a key role in the biosynthesis of some NRPSderived siderophores by the providing of an iron coordination moiety as the initial building block A new salicylate synthase namely AmS was identified in the biosynthesis pathway of siderophore amychelin in Amycolatopsis methanolica 239T since it shunt chorismate an integrant precursor from primary to secondary metabolite flow The amino acid sequence alignment and phylogenetic analysis showed that AmS grouped into a new cluster In vitro assays of AmS revealed its wide temperature tolerance ranged from 0 to 40 °C and narrow pH tolerant ranged from 70 to 90 AmS was resistant to organic solvents and nonionic detergents Moreover AmS converted chorismate to salicylate with K m of 12905 μM k cat of 220 min−1 at optimal conditions indicating its low substrate specificity and comparable velocity to reported counterparts Irp9 and MbtI These properties of AmS may improve the ironseizing ability of A methanolica to compete with its neighbors growing in natural environments Most importantly serine and cysteine residues were found to be important for the catalytic activity of AmS This study presented AmS as a new cluster of salicylate synthase and the reaction mechanism and potential applications of salicylate synthase were highlighted as wellThis work was supported in part by grants from the National Natural Science Foundation of China 31430002 31400090 31320103911 and 31125002 and the Ministry of Science and Technology of the People’s Republic of China 2011ZX1110201111 LZ is an awardee for the National Distinguished Young Scholar Program in China
Keywords: