The X-ray crystallographic structure and specificity profile of HAD superfamily phosphohydrolase BT1666: comparison of paralogous functions in B. thetaiotaomicron.

ABSTRACT: Analysis of the haloalkanoate dehalogenase superfamily (HADSF) has uncovered homologues occurring within the same organism that are found to possess broad, overlapping substrate specificities, and low catalytic efficiencies. Here we compare the HADSF phosphatase BT1666 from Bacteroides thetaiotaomicron VPI-5482 to a homologue with high sequence identity (40%) from the same organism BT4131, a known hexose-phosphate phosphatase. The goal is to find whether these enzymes represent duplicated versus paralogous activities. The X-ray crystal structure of BT1666 was determined to 1.82 Å resolution. Superposition of the BT1666 and BT4131 structures revealed a conserved fold and identical active sites suggestive of a common physiological substrate. The steady-state kinetic constants for BT1666 were

SUBMITTER: Lu Z 

PROVIDER: S-EPMC3356575 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature