7WRM image
Entry Detail
PDB ID:
7WRM
Title:
The malate-bound dimer of chemoreceptor MCP2201 ligand binding domain
Biological Source:
PDB Version:
Deposition Date:
2022-01-27
Release Date:
2023-01-04
Method Details:
Experimental Method:
Resolution:
1.80 Å
R-Value Free:
0.20
R-Value Work:
0.18
R-Value Observed:
0.18
Space Group:
P 21 21 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Methyl-accepting chemotaxis sensory transducer
Chain IDs:A, B
Chain Length:154
Number of Molecules:2
Biological Source:Comamonas testosteroni CNB-2
Ligand Molecules
Primary Citation
Attractant and repellent induce opposing changes in the four-helix bundle ligand-binding domain of a bacterial chemoreceptor.
Plos Biol. 21 e3002429 e3002429 (2023)
PMID: 38079456 DOI: 10.1371/journal.pbio.3002429

Abstact

Motile bacteria navigate toward favorable conditions and away from unfavorable environments using chemotaxis. Mechanisms of sensing attractants are well understood; however, molecular aspects of how bacteria sense repellents have not been established. Here, we identified malate as a repellent recognized by the MCP2201 chemoreceptor in a bacterium Comamonas testosteroni and showed that it binds to the same site as an attractant citrate. Binding determinants for a repellent and an attractant had only minor differences, and a single amino acid substitution in the binding site inverted the response to malate from a repellent to an attractant. We found that malate and citrate affect the oligomerization state of the ligand-binding domain in opposing way. We also observed opposing effects of repellent and attractant binding on the orientation of an alpha helix connecting the sensory domain to the transmembrane helix. We propose a model to illustrate how positive and negative signals might be generated.

Legend

Protein

Chemical

Disease

Primary Citation of related structures