2VA0

Differential regulation of the xylan degrading apparatus of Cellvibrio japonicus by a novel two component system

Summary for 2VA0

• Entry DOI: 10.2210/pdb2va0/pdb
• Descriptor: ABFS ARABINOFURANOSIDASE TWO COMPONENT SYSTEM SENSOR PROTEIN, PHOSPHATE ION, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: kinase, pas domain, transferase
• Biological source: CELLVIBRIO JAPONICUS
• Cellular location: Membrane; Multi-pass membrane protein (By similarity): B3PFT7
• Total number of polymer chains: 6
• Total formula weight: 92947.73

Authors

Murray, J.W.,Emami, K.,Topakas, E.,Nagy, T.,Henshaw, J.,Jackson, K.A.,Nelson, K.E.,Mongodin, E.F.,Lewis, R.J.,Gilbert, H.J. (deposition date: 2007-08-28, release date: 2008-10-14, Last modification date: 2024-05-08)

Primary citation

Emami, K.,Topakas, E.,Nagy, T.,Henshaw, J.,Jackson, K.A.,Nelson, K.E.,Mongodin, E.F.,Murray, J.W.,Lewis, R.J.,Gilbert, H.J.
Regulation of the Xylan-Degrading Apparatus of Cellvibrio Japonicus by a Novel Two-Component System.
J.Biol.Chem., 284:1086-, 2009

PubMed Abstract: The microbial degradation of lignocellulose biomass is not only an important biological process but is of increasing industrial significance in the bioenergy sector. The mechanism by which the plant cell wall, an insoluble composite structure, activates the extensive repertoire of microbial hydrolytic enzymes required to catalyze its degradation is poorly understood. Here we have used a transposon mutagenesis strategy to identify a genetic locus, consisting of two genes that modulate the expression of xylan side chain-degrading enzymes in the saprophytic bacterium Cellvibrio japonicus. Significantly, the locus encodes a two-component signaling system, designated AbfS (sensor histidine kinase) and AbfR (response regulator). The AbfR/S two-component system is required to activate the expression of the suite of enzymes that remove the numerous side chains from xylan, but not the xylanases that hydrolyze the beta1,4-linked xylose polymeric backbone of this polysaccharide. Studies on the recombinant sensor domain of AbfS (AbfS(SD)) showed that it bound to decorated xylans and arabinoxylo-oligosaccharides, but not to undecorated xylo-oligosaccharides or other plant structural polysaccharides/oligosaccharides. The crystal structure of AbfS(SD) was determined to a resolution of 2.6A(.) The overall fold of AbfS(SD) is that of a classical Per Arndt Sim domain with a central antiparallel four-stranded beta-sheet flanked by alpha-helices. Our data expand the number of molecules known to bind to the sensor domain of two-component histidine kinases to include complex carbohydrates. The biological rationale for a regulatory system that induces enzymes that remove the side chains of xylan, but not the hydrolases that cleave the backbone of the polysaccharide, is discussed.

PubMed: 18922794
DOI: 10.1074/JBC.M805100200

Experimental method

X-RAY DIFFRACTION (2.602 Å)