1bf6 | pdb_00001bf6
PHOSPHOTRIESTERASE HOMOLOGY PROTEIN FROM ESCHERICHIA COLI
Structural highlights
Function[PHP_ECOLI] Its real enzymatic activity is not yet known. It was tested for general esterase, aminopeptidase, sulfatase, phosphatase, carbonic anhydrase, phosphodiesterase, and phosphotriesterase activities with the following substrates: P-nitrophenyl acetate, L-alanine nitroanilide, P-nitrophenyl sulfate, bis(P-nitrophenyl) phosphate, paraoxon, and P-nitrophenyl phosphate. No enzymatic activity was detected with any of these nonspecific substrates. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPhosphotriesterase homology protein (PHP) is a member of a recently discovered family of proteins related to phosphotriesterase, a hydrolytic, bacterial enzyme with an unusual substrate specificity for synthetic organophosphate triesters and phosphorofluoridates, which are common constituents of chemical warfare agents and agricultural pesticides. No natural substrate has been identified for phosphotriesterase, and it has been suggested that the enzyme may have evolved the ability to hydrolyze synthetic compounds in bacteria under selective pressure to meet nutritional needs. PHP, which has 28% sequence identity with phosphotriesterase, may belong to the family of proteins from which phosphotriesterase evolved. Here we report the cloning, expression, initial characterization, and high-resolution X-ray crystallographic structure of PHP. Biochemical analysis shows that PHP is monomeric and binds two zinc ions per monomer. Unlike phosphotriesterase, PHP does not catalyze the hydrolysis of nonspecific phosphotriesters. The structure, similar to that of phosphotriesterase, consists of a long, elliptical alpha/beta barrel and has a binuclear zinc center in a cleft at the carboxy end of the barrel at the location of the presumptive active site. Biochemical characterization and crystallographic structure of an Escherichia coli protein from the phosphotriesterase gene family.,Buchbinder JL, Stephenson RC, Dresser MJ, Pitera JW, Scanlan TS, Fletterick RJ Biochemistry. 1998 Apr 14;37(15):5096-106. PMID:9548740[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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