4'-galactosyllactose-binding protein (BbrY_0420) (BbrY_0420)

BbrY_0420 is a substrate-binding protein (SBP) identified in Bifidobacterium breve strain Yakult, where it serves as a critical component of an ATP-binding cassette (ABC) transporter system (Oishi et al., 2015, PubMed). This protein is specifically responsible for the high-affinity recognition and capture of 4'-galactosyllactose (4'-GL) and 4-galactobiose (4-GB), which are major components of prebiotic galacto-oligosaccharides (GOS) (Oishi et al., 2015, PubMed). By facilitating the uptake of these non-digestible carbohydrates, BbrY_0420 enables B. breve to selectively proliferate in the human colon, outcompeting other microbiota members. This metabolic capability is linked to several health benefits, including the production of short-chain fatty acids like acetate, which helps prevent intestinal infections and modulate the host immune system (Microbiology Research, 2017). Furthermore, the utilization of GOS via this pathway has been associated with reduced risks of allergic diseases and obesity (Microbiology Research, 2017). While not a traditional drug target, BbrY_0420 is a primary target for prebiotic interventions aimed at enhancing gut health through microbiome engineering. Understanding its specificity allows for the design of more effective synbiotic formulations that combine specific probiotic strains with their preferred carbohydrate substrates.

Other names

BbrY_0420Solute-binding protein BbrY_04204'-GL-binding proteinGalacto-oligosaccharide-binding protein

High-affinity binding and delivery of 4'-galactosyllactose to the ABC transporter permease for cellular uptake.