ABC transporters: one, two or four extracytoplasmic substrate-binding sites?

ABSTRACT: Two families of ATP-binding cassette (ABC) transporters in which one or two extracytoplasmic substrate-binding domains are fused to either the N- or C-terminus of the translocator protein have been detected. This suggests that two, or even four, substrate-binding sites may function in the ABC transporter complex. This domain organization in ABC transporters, widely represented among microorganisms, raises new possibilities for how the substrate-binding protein(s) (SBPs) might interact with the translocator. One appealing hypothesis is that multiple substrate-binding sites in proximity to the entry site of the translocation pore enhance the transport capacity. We also discuss the implications of multiple substrate-binding sites in close proximity to the translocator in terms of broadened su

SUBMITTER: van der Heide T 

PROVIDER: S-EPMC1307614 | biostudies-literature | 2002 Oct

REPOSITORIES: biostudies-literature