Biochemical characterization of a new nicotinamidase from an unclassified bacterium thriving in a geothermal water stream microbial mat community.

ABSTRACT: Nicotinamidases are amidohydrolases that convert nicotinamide into nicotinic acid, contributing to NAD+ homeostasis in most organisms. In order to increase the number of nicotinamidases described to date, this manuscript characterizes a nicotinamidase obtained from a metagenomic library fosmid clone (JFF054_F02) obtained from a geothermal water stream microbial mat community in a Japanese epithermal mine. The enzyme showed an optimum temperature of 90°C, making it the first hyperthermophilic bacterial nicotinamidase to be characterized, since the phylogenetic analysis of this fosmid clone placed it in a clade of uncultured geothermal bacteria. The enzyme, named as UbNic, not only showed an alkaline optimum pH, but also a biphasic pH dependence of its kcat, with a maximum at pH 9.5-10.0. Th

SUBMITTER: Zapata-Perez R 

PROVIDER: S-EPMC5531466 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature