Enhancement of the alcoholytic activity of alpha-amylase AmyA from Thermotoga maritima MSB8 (DSM 3109) by site-directed mutagenesis.

AmyA, an alpha-amylase from the hyperthermophilic bacterium Thermotoga maritima, is able to hydrolyze internal alpha-1,4-glycosidic bonds in various alpha-glucans at 85 degrees C as the optimal temperature. Like other glycoside hydrolases, AmyA also catalyzes transglycosylation reactions, particularly when oligosaccharides are used as substrates. It was found that when methanol or butanol was used as the nucleophile instead of water, AmyA was able to catalyze alcoholysis reactions.