5XSJ

XylFII-LytSN complex

Summary for 5XSJ

• Entry DOI: 10.2210/pdb5xsj/pdb
• Descriptor: Periplasmic binding protein/LacI transcriptional regulator, Signal transduction histidine kinase, LytS, beta-D-xylopyranose, ... (4 entities in total)
• Functional Keywords: two component system, histidine kinase, signal transmission across the membrane, d-xylose uptake, sugar binding protein
• Biological source: Clostridium beijerinckii (strain ATCC 51743 / NCIMB 8052); More
• Total number of polymer chains: 2
• Total formula weight: 50787.15

Authors

Li, J.X.,Wang, C.Y.,Zhang, P. (deposition date: 2017-06-14, release date: 2017-08-02, Last modification date: 2024-05-29)

Primary citation

Li, J.,Wang, C.,Yang, G.,Sun, Z.,Guo, H.,Shao, K.,Gu, Y.,Jiang, W.,Zhang, P.
Molecular mechanism of environmental d-xylose perception by a XylFII-LytS complex in bacteria
Proc. Natl. Acad. Sci. U.S.A., 114:8235-8240, 2017

PubMed Abstract: d-xylose, the main building block of plant biomass, is a pentose sugar that can be used by bacteria as a carbon source for bio-based fuel and chemical production through fermentation. In bacteria, the first step for d-xylose metabolism is signal perception at the membrane. We previously identified a three-component system in bacteria comprising a membrane-associated sensor protein (XylFII), a transmembrane histidine kinase (LytS) for periplasmic d-xylose sensing, and a cytoplasmic response regulator (YesN) that activates the transcription of the target ABC transporter xylFGH genes to promote the uptake of d-xylose. The molecular mechanism underlying signal perception and integration of these processes remains elusive, however. Here we purified the N-terminal periplasmic domain of LytS (LytSN) in a complex with XylFII and determined the conformational structures of the complex in its d-xylose-free and d-xylose-bound forms. LytSN contains a four-helix bundle, and XylFII contains two Rossmann fold-like globular domains with a xylose-binding cleft between them. In the absence of d-xylose, LytSN and XylFII formed a heterodimer. Specific binding of d-xylose to the cleft of XylFII induced a large conformational change that closed the cleft and brought the globular domains closer together. This conformational change led to the formation of an active XylFII-LytSN heterotetramer. Mutations at the d-xylose binding site and the heterotetramer interface diminished heterotetramer formation and impaired the d-xylose-sensing function of XylFII-LytS. Based on these data, we propose a working model of XylFII-LytS that provides a molecular basis for d-xylose utilization and metabolic modification in bacteria.

PubMed: 28716923
DOI: 10.1073/pnas.1620183114

Experimental method

X-RAY DIFFRACTION (2.202 Å)