Discovery of two ?-1,2-mannoside phosphorylases showing different chain-length specificities from Thermoanaerobacter sp. X-514.

ABSTRACT: We characterized Teth514_1788 and Teth514_1789, belonging to glycoside hydrolase family 130, from Thermoanaerobacter sp. X-514. These two enzymes catalyzed the synthesis of 1,2-?-oligomannan using ?-1,2-mannobiose and d-mannose as the optimal acceptors, respectively, in the presence of the donor ?-d-mannose 1-phosphate. Kinetic analysis of the phosphorolytic reaction toward 1,2-?-oligomannan revealed that these enzymes followed a typical sequential Bi Bi mechanism. The kinetic parameters of the phosphorolysis of 1,2-?-oligomannan indicate that Teth514_1788 and Teth514_1789 prefer 1,2-?-oligomannans containing a DP ?3 and ?-1,2-Man2, respectively. These results indicate that the two enzymes are novel inverting phosphorylases that exhibit distinct chain-length specificities toward 1,2-?-oligomannan. Here, we propose 1,2-?-oligomannan:phosphate ?-d-mannosyltransferase as the systematic name and 1,2-?-oligomannan phosphorylase as the short name for Teth514_1788 and ?-1,2-mannobiose:phosphate ?-d-mannosyltransferase as the systematic name and ?-1,2-mannobiose phosphorylase as the short name for Teth514_1789.

SUBMITTER: Chiku K 

PROVIDER: S-EPMC4264767 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature