ArnR binds a [4Fe-4S] cluster and indirectly senses anaerobicity in Corynebacteria.

ABSTRACT: Corynebacteria are commercially and medically important Gram-positive bacteria that can switch from aerobic to anaerobic respiration in response to low O2 and the availability of nitrate as an alternative electron acceptor. The narKGHJI operon encoding the respiratory nitrate reductase is under the control of a novel regulator, ArnR, which plays a major role in the aerobic/anaerobic respiratory switch. ArnR was previously shown to be an iron-sulfur cluster protein that modulates its DNA binding according to availability of O2. However, previous data suggest that it does not do this directly in response to O2, but instead by sensing nitric oxide (NO), which builds up only under low O2 through the activity of nitrate reductase. Here, we report spectroscopic and mass spectrometric studies of

SUBMITTER: Crack JC 

PROVIDER: S-EPMC12343034 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature