5xs8

Publication Abstract from PubMed

Glycosaminoglycans (GAGs), constituted by repeating uronate and amino sugar units, are major components of mammalian extracellular matrices. Some indigenous and pathogenic bacteria target GAGs for colonization to and/or infection of host mammalian cells. In Gram-negative pathogenic Streptobacillus moniliformis, the solute-binding protein (Smon0123)-dependent ATP-binding cassette (ABC) transporter incorporates unsaturated GAG disaccharides into the cytoplasm after depolymerization by polysaccharide lyase. Smon0123, composed of N and C domains, adopts either a substrate-free open or a substrate-bound closed form by approaching two domains at 47 degrees in comparison with the open form. Here we show an alternative 39 degrees -closed conformation of Smon0123 bound to unsaturated chondroitin disaccharide sulfated at the C-4 and C-6 positions of N-acetyl-d-galactosamine residue (CDelta4S6S). In CDelta4S6S-bound Smon0123, Arg204 and Lys210 around the two sulfate groups were located at different positions from those at other substrate-bound 47 degrees -closed conformations. Therefore, the two sulfate groups in CDelta4S6S shifted substrate-binding residue arrangements, causing dynamic conformational change. Smon0123 showed less affinity with CDelta4S6S than with non-sulfated and monosulfated substrates. ATPase activity of the Smon0123-dependent ABC transporter in the presence of CDelta4S6S was lower than that in the presence of other unsaturated chondroitin disaccharides, suggesting that CDelta4S6S-bound Smon0123 was unpreferable for docking with the ABC transporter.

Alternative substrate-bound conformation of bacterial solute-binding protein involved in the import of mammalian host glycosaminoglycans.,Oiki S, Kamochi R, Mikami B, Murata K, Hashimoto W Sci Rep. 2017 Dec 5;7(1):17005. doi: 10.1038/s41598-017-16801-8. PMID:29208901^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.