Xylose-binding protein XylFII and sensor histidine kinase LytS complex (XylFII-LytS)

The Xylose-binding protein XylFII and sensor histidine kinase LytS complex (XylFII-LytS) is a bacterial signaling assembly that mediates the perception of environmental D-xylose, primarily characterized in Firmicutes such as Clostridium beijerinckii (Li et al., 2017). This complex is part of a three-component system that includes the cytoplasmic response regulator YesN (Gu et al., 2015). In the absence of xylose, XylFII and the N-terminal periplasmic domain of LytS (LytSN) form an inactive heterodimer (Li et al., 2017). Upon binding D-xylose, XylFII undergoes a significant conformational change—closing its binding cleft—which promotes the assembly of an active heterotetramer (PDB: 5XSJ). This structural transition activates the LytS histidine kinase, leading to the phosphorylation of YesN and the subsequent transcriptional activation of the xylFGH operon, which encodes a high-affinity xylose ABC transporter (Li et al., 2017). While not a traditional human therapeutic target, the XylFII-LytS complex is a critical target for metabolic engineering aimed at enhancing the efficiency of xylose fermentation for the production of biofuels and bio-based chemicals (Wang et al., 2019).

Other names

Bacterial xylose sensor complex XylFII-LytSNXylFII-LytSN complexXylose-sensing three-component systemXylFII-LytS-YesN systemBacterial xylose sensor