Substrate recognition by bacterial solute-binding protein is responsible for import of extracellular hyaluronan and chondroitin sulfate from the animal host.

Substrate recognition by bacterial solute-binding protein is responsible for import of extracellular hyaluronan and chondroitin sulfate from the animal host. Biosci Biotechnol Biochem. 2019 Jun 16;:1-9 Authors: Oiki S, Sato M, Mikami B, Murata K, Hashimoto W Abstract Glycosaminoglycans (GAGs) such as hyaluronan and chondroitin in animal extracellular matrices contain disaccharide-repeating units. In a Gram-negative pathogenic Streptobacillus moniliformis, which belongs to Fusobacteria phylum and resides in rodent oral cavities, the solute-binding protein (Smon0123)-dependent ATP-binding cassette transporter imports unsaturated hyaluronan/chondroitin disaccharides into the cytoplasm after GAG lyase-dependent depolymerization. Here we show substrate recognition of unsaturated hyaluronan disaccharide by Smon0123. Moreover, Smon0123 exhibited no affinity for unsaturated chondroitin disaccharides containing three sulfate groups, distinct from non-sulfated, mono-sulfated, and di-sulfated chondroitin disaccharides previously identified as substrates. Crystal structure of Smon0123 with unsaturated hyaluronan disaccharide demonstrates that several residues, including Trp284 and Glu410, are crucial for binding to unsaturated hyaluronan/chondroitin disaccharides, whereas arrangements of water molecules at binding sites are found to be substrate dependent through comparison with substrate-bound structures determined previously. These residues ar...
Source: Bioscience, Biotechnology, and Biochemistry - Category: Biochemistry Authors: Tags: Biosci Biotechnol Biochem Source Type: research