Molecular mechanism of environmental d-xylose perception by a XylFII-LytS complex in bacteria.
نویسندگان
چکیده
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 Firmicutes 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.
منابع مشابه
Differences in Intestinal Absorptive Capacity of Chickens for D-Xylose
Background: According to literature, there are differences among different species of animals in respect to absorption of D-xylose. OBJECTIVES: In two experiments, the differences that might exist in absorptive capacity of small intestine for D-xylose, in different types of chicken were tested. METHODS: In experiment one, 2 groups of nine adult layer type males (48 weeks) and females (58 weeks)...
متن کاملIsolation and Optimization of Ethanol Producing Bacteria from Natural Environments of Mazandaran Province in Iran
Ethanol producing bacteria are useful in industrial production of biofuel. There are interesting for screening of active bacteria from natural resources and introduce to biofuel industries. The present study aims to isolation of ethanol producing bacteria with characterization, optimization, and evaluation of their ethanol productivity. Samples from various fruits, plant saps and soils were scr...
متن کاملMolecular mechanism of xylose utilization in a plant growth-promoting bacterium Pseudomonas fluorescens SBW25
متن کامل
Establishment of oxidative D-xylose metabolism in Pseudomonas putida S12.
The oxidative D-xylose catabolic pathway of Caulobacter crescentus, encoded by the xylXABCD operon, was expressed in the gram-negative bacterium Pseudomonas putida S12. This engineered transformant strain was able to grow on D-xylose as a sole carbon source with a biomass yield of 53% (based on g [dry weight] g D-xylose(-1)) and a maximum growth rate of 0.21 h(-1). Remarkably, most of the genes...
متن کاملBacterial sugar utilization gives rise to distinct single-cell behaviours.
Inducible utilization pathways reflect widespread microbial strategies to uptake and consume sugars from the environment. Despite their broad importance and extensive characterization, little is known how these pathways naturally respond to their inducing sugar in individual cells. Here, we performed single-cell analyses to probe the behaviour of representative pathways in the model bacterium E...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 114 31 شماره
صفحات -
تاریخ انتشار 2017