6b90
Multiconformer model of apo WT PTP1B with glycerol at 100 K (ALTERNATIVE REFINEMENT OF PDB 1SUG showing conformational heterogeneity)Multiconformer model of apo WT PTP1B with glycerol at 100 K (ALTERNATIVE REFINEMENT OF PDB 1SUG showing conformational heterogeneity)
Structural highlights
Function[PTN1_HUMAN] Tyrosine-protein phosphatase which acts as a regulator of endoplasmic reticulum unfolded protein response. Mediates dephosphorylation of EIF2AK3/PERK; inactivating the protein kinase activity of EIF2AK3/PERK. May play an important role in CKII- and p60c-src-induced signal transduction cascades. May regulate the EFNA5-EPHA3 signaling pathway which modulates cell reorganization and cell-cell repulsion.[1] [2] Publication Abstract from PubMedProtein tyrosine phosphatase 1B (PTP1B) plays a key role as a negative regulator of insulin and leptin signalling and is therefore considered to be an important molecular target for the treatment of type 2 diabetes and obesity. Detailed structural information about the structure of PTP1B, including the conformation and flexibility of active-site residues as well as the water-molecule network, is a key issue in understanding ligand binding and enzyme kinetics and in structure-based drug design. A 1.95 A apo PTP1B structure has been obtained, showing four highly coordinated water molecules in the active-site pocket of the enzyme; hence, the active site is highly solvated in the apo state. Three of the water molecules are located at positions that approximately correspond to the positions of the phosphate O atoms of the natural substrate phosphotyrosine and form a similar network of hydrogen bonds. The active-site WPD-loop was found to be in the closed conformation, in contrast to previous observations of wild-type PTPs in the apo state, in which the WPD-loop is open. The closed conformation is stabilized by a network of hydrogen bonds. These results provide new insights into and understanding of the active site of PTP1B and form a novel basis for structure-based inhibitor design. Water-molecule network and active-site flexibility of apo protein tyrosine phosphatase 1B.,Pedersen AK, Peters G GH, Moller KB, Iversen LF, Kastrup JS Acta Crystallogr D Biol Crystallogr. 2004 Sep;60(Pt 9):1527-34. Epub 2004, Aug 26. PMID:15333922[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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