Arginine coordination in enzymatic phosphoryl transfer: evaluation of the effect of Arg166 mutations in Escherichia coli alkaline phosphatase.

ABSTRACT: Arginine residues are commonly found in the active sites of enzymes catalyzing phosphoryl transfer reactions. Numerous site-directed mutagenesis experiments establish the importance of these residues for efficient catalysis, but their role in catalysis is not clear. To examine the role of arginine residues in the phosphoryl transfer reaction, we have measured the consequences of mutations to arginine 166 in Escherichia coli alkaline phosphatase on hydrolysis of ethyl phosphate, on individual reaction steps in the hydrolysis of the covalent enzyme-phosphoryl intermediate, and on thio substitution effects. The results show that the role of the arginine side chain extends beyond its positive charge, as the Arg166Lys mutant is as compromised in activity as Arg166Ser. Through measurement of ind

SUBMITTER: O'Brien PJ 

PROVIDER: S-EPMC2587100 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature