Abstract
The major facilitator superfamily (MFS) represents the largest group of secondary active membrane transporters, and its members transport a diverse range of substrates. Recent work shows that MFS antiporters, and perhaps all members of the MFS, share the same three-dimensional structure, consisting of two domains that surround a substrate translocation pore. The advent of crystal structures of three MFS antiporters sheds light on their fundamental mechanism; they operate via a single binding site, alternating-access mechanism that involves a rocker-switch type movement of the two halves of the protein. In the sn-glycerol-3-phosphate transporter (GlpT) from Escherichia coli, the substrate-binding site is formed by several charged residues and a histidine that can be protonated. Salt-bridge formation and breakage are involved in the conformational changes of the protein during transport. In this review, we attempt to give an account of a set of mechanistic principles that characterize all MFS antiporters.
Original language | English (US) |
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Pages (from-to) | 289-305 |
Number of pages | 17 |
Journal | Annual review of microbiology |
Volume | 62 |
DOIs | |
State | Published - 2008 |
Externally published | Yes |
Keywords
- EmrD
- GlpT
- OxlT
- Rocker-switch mechanism
- Secondary membrane transporter proteins
- UhpT
ASJC Scopus subject areas
- Microbiology