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Structural and functional characterization of a novel phosphatase from the Arabidopsis thaliana gene locus At1g05000
Author(s) -
Aceti David J.,
Bitto Eduard,
Yakunin Alexander F.,
Proudfoot Michael,
Bingman Craig A.,
Frederick Ronnie O.,
Sreenath Hassan K.,
Vojtik Frank C.,
Wrobel Russell L.,
Fox Brian G.,
Markley John L.,
Phillips George N.
Publication year - 2008
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.22041
Subject(s) - cysteine , phosphatase , biochemistry , chemistry , phosphoenolpyruvate carboxykinase , divalent , biology , gene , enzyme , organic chemistry
The crystal structure of the protein product of the gene locus At1g05000, a hypothetical protein from A. thaliana, was determined by the multiple‐wavelength anomalous diffraction method and was refined to an R factor of 20.4% (R free = 24.9%) at 3.3 Å. The protein adopts the α/β fold found in cysteine phosphatases, a superfamily of phosphatases that possess a catalytic cysteine and form a covalent thiol‐phosphate intermediate during the catalytic cycle. In At1g05000, the analogous cysteine (Cys 150 ) is located at the bottom of a positively‐charged pocket formed by residues that include the conserved arginine (Arg 156 ) of the signature active site motif, HCxxGxxRT. Of 74 model phosphatase substrates tested, purified recombinant At1g05000 showed highest activity toward polyphosphate (poly‐P 12‐13 ) and deoxyribo‐ and ribonucleoside triphosphates, and less activity toward phosphoenolpyruvate, phosphotyrosine, phosphotyrosine‐containing peptides, and phosphatidyl inositols. Divalent metal cations were not required for activity and had little effect on the reaction. Proteins 2008. © 2008 Wiley‐Liss, Inc.