A bacterial NO-binding sensor domain evolved through acquisition of a cytochrome-derived c-type heme-binding motif.

ABSTRACT: Diverse bacterial sensory domains detect intracellular and extracellular cues and relay this information to downstream signaling pathways. Per-Arnt-Sim (PAS) domains are well known to bind cofactors such as heme for intracellular sensing, whereas Cache domains - the largest family of bacterial extracytoplasmic sensor modules - are thought to function exclusively as cofactor-independent ligand-binding domains. Here, we identify and characterize a large family of Cache domains that contain a covalently bound c-type heme. Systematic sequence analysis of the DUF3365/Tll0287 family of unknown function reveals exceptional conservation of a canonical CXXCH heme-binding motif, establishing c-type heme binding as a defining feature of this domain family. Structure- and sequence-based comparisons de

SUBMITTER: Deshpande M 

PROVIDER: S-EPMC12889525 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature