An annular lipid belt is essential for allosteric coupling and viral inhibition of the antigen translocation complex TAP (transporter associated with antigen processing).

ABSTRACT: The transporter associated with antigen processing (TAP) constitutes a focal element in the adaptive immune response against infected or malignantly transformed cells. TAP shuttles proteasomal degradation products into the lumen of the endoplasmic reticulum for loading of major histocompatibility complex (MHC) class I molecules. Here, the heterodimeric TAP complex was purified and reconstituted in nanodiscs in defined stoichiometry. We demonstrate that a single heterodimeric core-TAP complex is active in peptide binding, which is tightly coupled to ATP hydrolysis. Notably, with increasing peptide length, the ATP turnover was gradually decreased, revealing that ATP hydrolysis is coupled to the movement of peptide through the ATP-binding cassette transporter. In addition, all-atom molecular

SUBMITTER: Eggensperger S 

PROVIDER: S-EPMC4246070 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature