1l9m | pdb_00001l9m

Three-dimensional structure of the human transglutaminase 3 enzyme: binding of calcium ions change structure for activation

spinqualitylabelsall models 1l9m, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1l9m is a 2 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BR, CA, CL Related: 1l9n Gene: TGM3 (HUMAN) Activity: Protein-glutamine gamma-glutamyltransferase, with EC number 2.3.2.13 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [TGM3_HUMAN] Catalyzes the calcium-dependent formation of isopeptide cross-links between glutamine and lysine residues in various proteins, as well as the conjugation of polyamines to proteins. Involved in the formation of the cornified envelope (CE), a specialized component consisting of covalent cross-links of proteins beneath the plasma membrane of terminally differentiated keratinocytes. Catalyzes small proline-rich proteins (SPRR1 and SPRR2) and LOR cross-linking to form small interchain oligomers, which are further cross-linked by TGM1 onto the growing CE scaffold (By similarity). In hair follicles, involved in cross-linking structural proteins to hardening the inner root sheath. 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 PubMed Transglutaminase (TGase) enzymes catalyze the formation of covalent cross-links between protein-bound glutamines and lysines in a calcium-dependent manner, but the role of Ca(2+) ions remains unclear. The TGase 3 isoform is widely expressed and is important for epithelial barrier formation. It is a zymogen, requiring proteolysis for activity. We have solved the three-dimensional structures of the zymogen and the activated forms at 2.2 and 2.1 A resolution, respectively, and examined the role of Ca(2+) ions. The zymogen binds one ion tightly that cannot be exchanged. Upon proteolysis, the enzyme exothermally acquires two more Ca(2+) ions that activate the enzyme, are exchangeable and are functionally replaceable by other lanthanide trivalent cations. Binding of a Ca(2+) ion at one of these sites opens a channel which exposes the key Trp236 and Trp327 residues that control substrate access to the active site. Together, these biochemical and structural data reveal for the first time in a TGase enzyme that Ca(2+) ions induce structural changes which at least in part dictate activity and, moreover, may confer substrate specificity. Three-dimensional structure of the human transglutaminase 3 enzyme: binding of calcium ions changes structure for activation.,Ahvazi B, Kim HC, Kee SH, Nemes Z, Steinert PM EMBO J. 2002 May 1;21(9):2055-67. PMID:11980702 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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