Structural highlights
Function
[ULAA_ECOLI] The phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS), a major carbohydrate active-transport system, catalyzes the phosphorylation of incoming sugar substrates concomitant with their translocation across the cell membrane. This system is involved in ascorbate transport.
Publication Abstract from PubMed
Bacteria use vitamin C (L-ascorbic acid) as a carbon source under anaerobic conditions. The phosphoenolpyruvate-dependent phosphotransferase system (PTS), comprising a transporter (UlaA), a IIB-like enzyme (UlaB) and a IIA-like enzyme (UlaC), is required for the anaerobic uptake of vitamin C and its phosphorylation to L-ascorbate 6-phosphate. Here, we present the crystal structures of vitamin C-bound UlaA from Escherichia coli in two conformations at 1.65-A and 2.35-A resolution. UlaA forms a homodimer and exhibits a new fold. Each UlaA protomer consists of 11 transmembrane segments arranged into a 'V-motif' domain and a 'core' domain. The V motifs form the interface between the two protomers, and the core-domain residues coordinate vitamin C. The alternating access of the substrate from the opposite side of the cell membrane may be achieved through rigid-body rotation of the core relative to the V motif.
Crystal structure of a phosphorylation-coupled vitamin C transporter.,Luo P, Yu X, Wang W, Fan S, Li X, Wang J Nat Struct Mol Biol. 2015 Feb 16. doi: 10.1038/nsmb.2975. PMID:25686089[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Luo P, Yu X, Wang W, Fan S, Li X, Wang J. Crystal structure of a phosphorylation-coupled vitamin C transporter. Nat Struct Mol Biol. 2015 Feb 16. doi: 10.1038/nsmb.2975. PMID:25686089 doi:https://dx.doi.org/10.1038/nsmb.2975
