7W0W

The novel membrane-proximal sensing mechanism in a broad-ligand binding chemoreceptor McpA of Bacillus velezensis

Summary for 7W0W

• Entry DOI: 10.2210/pdb7w0w/pdb
• Descriptor: Methyl-accepting chemotaxis protein, (2S)-2-hydroxybutanedioic acid, 1,2-ETHANEDIOL, ... (6 entities in total)
• Functional Keywords: chemoreceptor, ligand-binding domain, dcache, malic acid, protein binding
• Biological source: Bacillus velezensis
• Total number of polymer chains: 2
• Total formula weight: 47166.96

Authors

Feng, H.C.,Shen, Q.R.,Zhang, R.F. (deposition date: 2021-11-18, release date: 2022-07-06, Last modification date: 2023-11-29)

Primary citation

Feng, H.,Lv, Y.,Krell, T.,Fu, R.,Liu, Y.,Xu, Z.,Du, W.,Shen, Q.,Zhang, N.,Zhang, R.
Signal binding at both modules of its dCache domain enables the McpA chemoreceptor of Bacillus velezensis to sense different ligands.
Proc.Natl.Acad.Sci.USA, 119:e2201747119-e2201747119, 2022

PubMed Abstract: Bacteria have evolved multiple signal transduction systems that permit an adaptation to changing environmental conditions. Chemoreceptor-based signaling cascades are very abundant in bacteria and are among the most complex signaling systems. Currently, our knowledge on the molecular features that determine signal recognition at chemoreceptors is limited. Chemoreceptor McpA of SQR9 has been shown to mediate chemotaxis to a broad range of different ligands. Here we show that its ligand binding domain binds directly 13 chemoattractants. We provide support that organic acids and amino acids bind to the membrane-distal and membrane-proximal module of the dCache domain, respectively, whereas binding of sugars/sugar alcohols occurred at both modules. Structural biology studies combined with site-directed mutagenesis experiments have permitted to identify 10 amino acid residues that play key roles in the recognition of multiple ligands. Residues in membrane-distal and membrane-proximal regions were central for sensing organic acids and amimo acids, respectively, whereas all residues participated in sugars/sugar alcohol sensing. Most characterized chemoreceptors possess a narrow and well-defined ligand spectrum. We propose here a sensing mechanism involving both dCache modules that allows the integration of very diverse signals by a single chemoreceptor.

PubMed: 35858353
DOI: 10.1073/pnas.2201747119

Experimental method

X-RAY DIFFRACTION (2.247 Å)