HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zhang, Z. Articles by Van Etten, R. L. Search for Related Content PubMed PubMed Citation Articles by Zhang, Z. Articles by Van Etten, R. L. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 269, Issue 42, 25947-25950, 10, 1994

Asp129 of low molecular weight protein tyrosine phosphatase is involved in leaving group protonation

Z Zhang, E Harms and RL Van Etten
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907.

Site-directed mutagenesis was used to explore the functions of a number of acidic residues of bovine low molecular weight protein tyrosine phosphatase. Residues Asp-129, Asp-56, and Asp-92 were mutated to Ala or Asn. The mutant enzymes D56A, D56N, and D92A showed no significant changes in Vmax values, although they did exhibit significantly altered Km values. In contrast, the D129A mutant enzyme exhibited a greater than 2000-fold reduction in Vmax, using p-nitrophenyl phosphate as a substrate. The Vmax values of D129A also exhibited a leaving group dependence, an altered solvent isotope effect of VmaxH/VmaxD of 0.78, and a lack of dependence on the presence of alternative phosphate acceptor alcohols, all properties that distinguish this mutant from wild type enzyme. The differences are due to a change of the rate- limiting step of the catalytic reaction. Asp-129 is concluded to be the proton donor to the leaving group in the phosphorylation step, and its mutation to alanine results in a reduced Vmax value and a change in the rate-limiting step of the catalysis from dephosphorylation to phosphorylation. Mechanistic considerations suggest that other phosphotyrosyl phosphatases having cysteine at the active site may be expected to have a similar requirement for a proton donor.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				E. Lescop, Y. Hu, H. Xu, W. Hu, J. Chen, B. Xia, and C. Jin The Solution Structure of Escherichia coli Wzb Reveals a Novel Substrate Recognition Mechanism of Prokaryotic Low Molecular Weight Protein-tyrosine Phosphatases J. Biol. Chem., July 14, 2006; 281(28): 19570 - 19577. [Abstract] [Full Text] [PDF]

				A. P. R. Zabell, A. D. Schroff Jr., B. E. Bain, R. L. Van Etten, O. Wiest, and C. V. Stauffacher Crystal Structure of the Human B-form Low Molecular Weight Phosphotyrosyl Phosphatase at 1.6-A Resolution J. Biol. Chem., March 10, 2006; 281(10): 6520 - 6527. [Abstract] [Full Text] [PDF]

				H. Xu, B. Xia, and C. Jin Solution Structure of a Low-Molecular-Weight Protein Tyrosine Phosphatase from Bacillus subtilis J. Bacteriol., February 15, 2006; 188(4): 1509 - 1517. [Abstract] [Full Text] [PDF]

				S. Veeramani, T.-C. Yuan, S.-J. Chen, F.-F. Lin, J. E Petersen, S. Shaheduzzaman, S. Srivastava, R. G MacDonald, and M.-F. Lin Cellular prostatic acid phosphatase: a protein tyrosine phosphatase involved in androgen-independent proliferation of prostate cancer Endocr. Relat. Cancer, December 1, 2005; 12(4): 805 - 822. [Abstract] [Full Text] [PDF]

				C. Madhurantakam, E. Rajakumara, P. A. Mazumdar, B. Saha, D. Mitra, H. G. Wiker, R. Sankaranarayanan, and A. K. Das Crystal Structure of Low-Molecular-Weight Protein Tyrosine Phosphatase from Mycobacterium tuberculosis at 1.9-A Resolution J. Bacteriol., March 15, 2005; 187(6): 2175 - 2181. [Abstract] [Full Text] [PDF]

				P. M. Legler, M. Cai, A. Peterkofsky, and G. M. Clore Three-dimensional Solution Structure of the Cytoplasmic B Domain of the Mannitol Transporter IIMannitol of the Escherichia coli Phosphotransferase System J. Biol. Chem., September 10, 2004; 279(37): 39115 - 39121. [Abstract] [Full Text] [PDF]

				W.-Q. Wang, J. Bembenek, K. R. Gee, H. Yu, H. Charbonneau, and Z.-Y. Zhang Kinetic and Mechanistic Studies of a Cell Cycle Protein Phosphatase Cdc14 J. Biol. Chem., July 16, 2004; 279(29): 30459 - 30468. [Abstract] [Full Text] [PDF]

				A. Meinhart, T. Silberzahn, and P. Cramer The mRNA Transcription/Processing Factor Ssu72 Is a Potential Tyrosine Phosphatase J. Biol. Chem., April 25, 2003; 278(18): 15917 - 15921. [Abstract] [Full Text] [PDF]

				K. D. Kikawa, D. R. Vidale, R. L. Van Etten, and M. S. Kinch Regulation of the EphA2 Kinase by the Low Molecular Weight Tyrosine Phosphatase Induces Transformation J. Biol. Chem., October 11, 2002; 277(42): 39274 - 39279. [Abstract] [Full Text] [PDF]

				D. F. McCain, I. E. Catrina, A. C. Hengge, and Z.-Y. Zhang The Catalytic Mechanism of Cdc25A Phosphatase J. Biol. Chem., March 22, 2002; 277(13): 11190 - 11200. [Abstract] [Full Text] [PDF]

				M. Zhang, C. V. Stauffacher, D. Lin, and R. L. Van Etten Crystal Structure of a Human Low Molecular Weight Phosphotyrosyl Phosphatase. IMPLICATIONS FOR SUBSTRATE SPECIFICITY J. Biol. Chem., August 21, 1998; 273(34): 21714 - 21720. [Abstract] [Full Text] [PDF]

				K. Ostanin, C. Pokalsky, S. Wang, and R. L. Van Etten Cloning and Characterization of a Saccharomyces cerevisiae Gene Encoding the Low Molecular Weight Protein-tyrosine Phosphatase J. Biol. Chem., August 4, 1995; 270(31): 18491 - 18499. [Abstract] [Full Text] [PDF]

				Z Jia, D Barford, A. Flint, and N. Tonks Structural basis for phosphotyrosine peptide recognition by protein tyrosine phosphatase 1B Science, June 23, 1995; 268(5218): 1754 - 1758. [Abstract] [PDF]