Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2004-2-17
pubmed:databankReference
pubmed:abstractText
Transglutaminase 3 (TGase 3) is a member of a family of Ca2+-dependent enzymes that catalyze covalent cross-linking reactions between proteins or peptides. TGase 3 isoform is widely expressed and is important for effective epithelial barrier formation in the assembly of the cell envelope. Among the nine TGase enzyme isoforms known in the human genome, only TGase 2 is known to bind and hydrolyze GTP to GDP; binding GTP inhibits its transamidation activity but allows it to function in signal transduction. Here we present biochemical and crystallographic evidence for the direct binding of GTP/GDP to the active TGase 3 enzyme, and we show that the TGase 3 enzyme undergoes a GTPase cycle. The crystal structures of active TGase 3 with guanosine 5'-O-(thiotriphosphate) (GTPgammaS) and GDP were determined to 2.1 and 1.9 A resolution, respectively. These studies reveal for the first time the reciprocal actions of Ca2+ and GTP with respect to TGase 3 activity. GTPgammaS binding is coordinated with the replacement of a bound Ca2+ with Mg2+ and conformational rearrangements that together close a central channel to the active site. Hydrolysis of GTP to GDP results in two stable conformations, resembling both the GTP state and the non-nucleotide bound state, the latter of which allows substrate access to the active site.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7180-92
pubmed:dateRevised
2007-5-21
pubmed:meshHeading
pubmed-meshheading:14645372-Amino Acid Sequence, pubmed-meshheading:14645372-Binding Sites, pubmed-meshheading:14645372-Calcium, pubmed-meshheading:14645372-Calcium-Binding Proteins, pubmed-meshheading:14645372-Calorimetry, pubmed-meshheading:14645372-Crystallography, X-Ray, pubmed-meshheading:14645372-Dose-Response Relationship, Drug, pubmed-meshheading:14645372-Gene Expression Regulation, Enzymologic, pubmed-meshheading:14645372-Genome, pubmed-meshheading:14645372-Guanosine 5'-O-(3-Thiotriphosphate), pubmed-meshheading:14645372-Guanosine Diphosphate, pubmed-meshheading:14645372-Guanosine Triphosphate, pubmed-meshheading:14645372-Humans, pubmed-meshheading:14645372-Hydrolysis, pubmed-meshheading:14645372-Ions, pubmed-meshheading:14645372-Kinetics, pubmed-meshheading:14645372-Magnesium, pubmed-meshheading:14645372-Models, Molecular, pubmed-meshheading:14645372-Molecular Sequence Data, pubmed-meshheading:14645372-Protein Binding, pubmed-meshheading:14645372-Protein Conformation, pubmed-meshheading:14645372-Protein Isoforms, pubmed-meshheading:14645372-Recombinant Proteins, pubmed-meshheading:14645372-Signal Transduction, pubmed-meshheading:14645372-Substrate Specificity, pubmed-meshheading:14645372-Thermodynamics, pubmed-meshheading:14645372-Time Factors, pubmed-meshheading:14645372-Transglutaminases
pubmed:year
2004
pubmed:articleTitle
Structural basis for the coordinated regulation of transglutaminase 3 by guanine nucleotides and calcium/magnesium.
pubmed:affiliation
X-ray Crystallography Facility/Office of Science and Technology, NIAMS, National Institutes of Health, Bethesda, Maryland 20892-8023, USA. ahvazib@mail.nih.gov
pubmed:publicationType
Journal Article