1jln
Crystal structure of the catalytic domain of protein tyrosine phosphatase PTP-SL/BR7
Structural highlights
FunctionPTPRR_MOUSE Sequesters mitogen-activated protein kinases (MAPKs) such as MAPK1, MAPK3 and MAPK14 in the cytoplasm in an inactive form. The MAPKs bind to a dephosphorylated kinase interacting motif, phosphorylation of which by the protein kinase A complex releases the MAPKs for activation and translocation into the nucleus. Isoform gamma may have a role in patterning and cellular proliferation of skeletal elements in the precartilaginous/cartilaginous skeleton.[1] [2] 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 PubMedProtein tyrosine phosphatases PTP-SL and PTPBR7 are isoforms belonging to cytosolic membrane-associated and to receptor-like PTPs (RPTPs), respectively. They represent a new family of PTPs with a major role in activation and translocation of MAP kinases. Specifically, the complex formation between PTP-SL and ERK2 involves an unusual interaction leading to the phosphorylation of PTP-SL by ERK2 at Thr253 and the inactivating dephosphorylation of ERK2 by PTP-SL. This interaction is strictly dependent upon a kinase interaction motif (KIM) (residues 224-239) situated at the N terminus of the PTP-SL catalytic domain. We report the first crystal structure of the catalytic domain for a member of this family (PTP-SL, residues 254-549, identical with residues 361-656 of PTPBR7), providing an example of an RPTP with single cytoplasmic domain, which is monomeric, having an unhindered catalytic site. In addition to the characteristic PTP-core structure, PTP-SL has an N-terminal helix, possibly orienting the KIM motif upon interaction with the target ERK2. An unusual residue in the catalytically important WPD loop promotes formation of a hydrophobically and electrostatically stabilised clamp. This could induce increased rigidity to the WPD loop and therefore reduced catalytic activity, in agreement with our kinetic measurements. A docking model based on the PTP-SL structure suggests that, in the complex with ERK2, the phosphorylation of PTP-SL should be accomplished first. The subsequent dephosphorylation of ERK2 seems to be possible only if a conformational rearrangement of the two interacting partners takes place. Crystal structure of PTP-SL/PTPBR7 catalytic domain: implications for MAP kinase regulation.,Szedlacsek SE, Aricescu AR, Fulga TA, Renault L, Scheidig AJ J Mol Biol. 2001 Aug 17;311(3):557-68. PMID:11493009[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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