Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-12-21
pubmed:abstractText
TAP delivers antigenic peptides into the endoplasmic reticulum (ER) that are subsequently bound by MHC class I molecules. TAP consists of two subunits (TAP1 and TAP2), each with a transmembrane (TMD) and a nucleotide-binding (NBD) domain. The two TAP-NBDs have distinct biochemical properties and control different steps during the peptide translocation process. We noted previously that the nonhomologous C-terminal tails of rat TAP1 and TAP2 determine the distinct functions of TAP-NBD1 and -NBD2. To identify the sequence elements responsible for the asymmetrical NBD function, we constructed chimeric rat TAP variants in which we systematically exchanged sequence regions of different length between the two TAP-NBDs. Our fine-mapping studies demonstrate that a nonhomologous region containing the alpha6/beta10-loop in conjunction with the downstream switch region is directly responsible for the functional separation of the TAP-NBDs. The alpha6/beta10-loop determines the nonsynonymous nucleotide binding of NBD1 and NBD2, whereas the switch region seems to play a critical role in regulating the functional cross-talk between the structural domains of TAP. Based on our findings, we postulate that these two sequence elements build a minimal functional unit that controls the asymmetry of the two TAP-NBDs.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
174
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
328-39
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Functional role of C-terminal sequence elements in the transporter associated with antigen processing.
pubmed:affiliation
Institute for Genetics, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't