Publication Abstract from PubMed
Tissue transglutaminase (TG) is a Ca2+-dependent acyltransferase with roles in cellular differentiation, apoptosis, and other biological functions. In addition to being a transamidase, TG undergoes a GTP-binding/GTPase cycle even though it lacks any obvious sequence similarity with canonical GTP-binding (G) proteins. Guanine nucleotide binding and Ca2+ concentration reciprocally regulate TG's transamidation activity, with nucleotide binding being the negative regulator. Here we report the x-ray structure determined to 2.8-A resolution of human TG complexed with GDP. Although the transamidation active site is similar to those of other known transglutaminases, the guanine nucleotide-binding site of TG differs markedly from other G proteins. The structure suggests a structural basis for the negative regulation of transamidation activity by bound nucleotide, and the positive regulation of transamidation by Ca2+.
Structural basis for the guanine nucleotide-binding activity of tissue transglutaminase and its regulation of transamidation activity.,Liu S, Cerione RA, Clardy J Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):2743-7. Epub 2002 Feb 26. PMID:11867708[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
