Structural basis for allosteric cross-talk between the asymmetric nucleotide binding sites of a heterodimeric ABC exporter.

ABSTRACT: ATP binding cassette (ABC) transporters mediate vital transport processes in every living cell. ATP hydrolysis, which fuels transport, displays positive cooperativity in numerous ABC transporters. In particular, heterodimeric ABC exporters exhibit pronounced allosteric coupling between a catalytically impaired degenerate site, where nucleotides bind tightly, and a consensus site, at which ATP is hydrolyzed in every transport cycle. Whereas the functional phenomenon of cooperativity is well described, its structural basis remains poorly understood. Here, we present the apo structure of the heterodimeric ABC exporter TM287/288 and compare it to the previously solved structure with adenosine 5'-(β,γ-imido)triphosphate (AMP-PNP) bound at the degenerate site. In contrast to other ABC exporter s

SUBMITTER: Hohl M 

PROVIDER: S-EPMC4121816 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature