4'-galactosyllactose-binding protein BbrY_0420 (BbrY_0420)

4'-galactosyllactose-binding protein BbrY_0420 is a specialized solute-binding protein (SBP) found in Bifidobacterium breve strain Yakult (YIT 4014) (Source [1]). It serves as the primary recognition and capture component of an ATP-binding cassette (ABC) transporter system that enables the bacterium to utilize specific galacto-oligosaccharides (GOS) (Source [5]). The protein exhibits high substrate specificity and strong affinity for 4'-galactosyllactose (4'-GL) and 4-galactobiose (4-GB), specifically recognizing the Galβ1,4-Gal non-reducing terminal structure (Source [1]). BbrY_0420 is co-induced with the β-galactosidase BbrY_0422, ensuring that captured oligosaccharides are efficiently transported and subsequently hydrolyzed for energy (Source [1]). This transport system provides a competitive advantage for B. breve in the human colon, where it scavenges non-digestible dietary fibers that reach the lower gastrointestinal tract intact (Source [5]). By facilitating the selective growth of beneficial bifidobacteria, BbrY_0420 plays a crucial role in maintaining a healthy gut microbiome and modulating host immune responses (Source [5]). Increased abundance of B. breve mediated by this pathway is associated with reduced risks of enteric infection, chronic inflammation, and allergic diseases (Source [5]). Consequently, BbrY_0420 is a significant molecular target for prebiotic strategies and nutritional interventions aimed at fostering beneficial microbial populations for therapeutic benefit (Source [1], [7]).

Other names

Solute-binding protein BbrY_0420BbrY_04204'-GL-binding proteinBacterial substrate-binding protein BbrY_0420ABC transporter substrate-binding protein BbrY_0420

Selective binding and delivery of specific galacto-oligosaccharides to the transmembrane domains of an ABC transporter for cellular uptake and subsequent metabolic utilization (Source [1], [5]).