Dual specificity protein phosphatases (DSPs) regulate mitogenic signal transduction and control the cell cycle. Here, the crystal structure of a human DSP, vaccinia H1-related phosphatase (or VHR), was determined at 2.1 angstrom resolution. A shallow active site pocket in VHR allows for the hydrolysis of phosphorylated serine, threonine, or tyrosine protein residues, whereas the deeper active site of protein tyrosine phosphatases (PTPs) restricts substrate specificity to only phosphotyrosine ...
Dual specificity protein phosphatases (DSPs) regulate mitogenic signal transduction and control the cell cycle. Here, the crystal structure of a human DSP, vaccinia H1-related phosphatase (or VHR), was determined at 2.1 angstrom resolution. A shallow active site pocket in VHR allows for the hydrolysis of phosphorylated serine, threonine, or tyrosine protein residues, whereas the deeper active site of protein tyrosine phosphatases (PTPs) restricts substrate specificity to only phosphotyrosine. Positively charged crevices near the active site may explain the enzyme's preference for substrates with two phosphorylated residues. The VHR structure defines a conserved structural scaffold for both DSPs and PTPs. A "recognition region," connecting helix alpha1 to strand beta1, may determine differences in substrate specificity between VHR, the PTPs, and other DSPs.
Related Citations:
The Purification and Characterization of a Human Dual-Specific Protein Tyrosine Phosphatase Denu, J.M., Zhou, G., Wu, L., Zhao, R., Yuvaniyama, J., Saper, M.A., Dixon, J.E. (1995) J Biol Chem 270: 3796
The Catalytic Role of Cys124 in the Dual Specificity Phosphatase Vhr Zhou, G., Denu, J.M., Wu, L., Dixon, J.E. (1994) J Biol Chem 269: 28084
Expression Cloning of a Human Dual-Specificity Phosphatase Ishibashi, T., Bottaro, D.P., Chan, A., Miki, T., Aaronson, S.A. (1992) Proc Natl Acad Sci U S A 89: 12170
Organizational Affiliation:
Biophysics Research Division and Department of Biological Chemistry, University of Michigan, Ann Arbor 48109-1055, USA.
Download Mendeley
