Succinate-acetate permease from Citrobacter koseri is an anion channel that unidirectionally translocates acetate.

ABSTRACT: Acetate is an important metabolite in metabolism and cell signaling. Succinate-Acetate Permease (SatP) superfamily proteins are known to be responsible for acetate transport across membranes, but the nature of this transport remains unknown. Here, we show that the SatP homolog from Citrobacter koseri (SatP_Ck) is an anion channel that can unidirectionally translocate acetate at rates of the order of ~10⁷ ions/s. Crystal structures of SatP_Ck in complex with multiple acetates at 1.8 Å reveal that the acetate pathway consists of four acetate-binding sites aligned in a single file that are interrupted by three hydrophobic constrictions. The bound acetates at the four sites are each orientated differently. The acetate at the cytoplasmic vestibule is partially dehydrated, whereas tho

SUBMITTER: Qiu B 

PROVIDER: S-EPMC5993801 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature