2ixe

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spinqualitylabelsall models 2ixe, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF THE ATPASE DOMAIN OF TAP1 WITH ATP (D645N MUTANT)

Overview

The ABC transporter associated with antigen processing (TAP) shuttles, cytosolic peptides into the endoplasmic reticulum for loading onto class I, MHC molecules. Transport is fueled by ATP binding and hydrolysis at two, distinct cytosolic ATPase sites. One site comprises consensus motifs, shared among most ABC transporters, while the second has substituted, degenerate motifs. Biochemical and crystallography experiments with a TAP, cytosolic domain demonstrate that the consensus ATPase site has high, catalytic activity and facilitates ATP-dependent dimerization of the, cytosolic domains, which is an important conformational change during, transport. In contrast, the degenerate site is defective in dimerization, and ATP hydrolysis. Full-length TAP mutagenesis demonstrates the necessity, for at least one consensus site, supporting our conclusion that the, consensus site is the principal facilitator of substrate transport. Since, asymmetry of the ATPase site motifs is a feature of many mammalian, homologs, our proposed model has broad implications for ABC transporters.

About this Structure

2IXE is a Single protein structure of sequence from Rattus norvegicus with MG, PO4 and ATP as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.

Reference

Distinct structural and functional properties of the ATPase sites in an asymmetric ABC transporter., Procko E, Ferrin-O'Connell I, Ng SL, Gaudet R, Mol Cell. 2006 Oct 6;24(1):51-62. PMID:17018292

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