The Molecular Mechanism of Nitrate Chemotaxis via Direct Ligand Binding to the PilJ Domain of McpN.

ABSTRACT: Chemotaxis and energy taxis permit directed bacterial movements in gradients of environmental cues. Nitrate is a final electron acceptor for anaerobic respiration and can also serve as a nitrogen source for aerobic growth. Previous studies indicated that bacterial nitrate taxis is mediated by energy taxis mechanisms, which are based on the cytosolic detection of consequences of nitrate metabolism. Here we show that Pseudomonas aeruginosa PAO1 mediates nitrate chemotaxis on the basis of specific nitrate sensing by the periplasmic PilJ domain of the PA2788/McpN chemoreceptor. The presence of nitrate reduced mcpN transcript levels, and McpN-mediated taxis occurred only under nitrate starvation conditions. In contrast to the NarX and NarQ sensor kinases, McpN bound nitrate specif

SUBMITTER: Martin-Mora D 

PROVIDER: S-EPMC6381276 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature