Differential active site loop conformations mediate promiscuous activities in the lactonase SsoPox.

ABSTRACT: Enzymes are proficient catalysts that enable fast rates of Michaelis-complex formation, the chemical step and products release. These different steps may require different conformational states of the active site that have distinct binding properties. Moreover, the conformational flexibility of the active site mediates alternative, promiscuous functions. Here we focused on the lactonase SsoPox from Sulfolobus solfataricus. SsoPox is a native lactonase endowed with promiscuous phosphotriesterase activity. We identified a position in the active site loop (W263) that governs its flexibility, and thereby affects the substrate specificity of the enzyme. We isolated two different sets of substitutions at position 263 that induce two distinct conformational sampling of the active loop and charact

SUBMITTER: Hiblot J 

PROVIDER: S-EPMC3781021 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature