Mycobacterium tuberculosis DosS binds H₂S through its Fe³⁺ heme iron to regulate the DosR dormancy regulon.

ABSTRACT: Mycobacterium tuberculosis (Mtb) senses and responds to host-derived gasotransmitters NO and CO via heme-containing sensor kinases DosS and DosT and the response regulator DosR. Hydrogen sulfide (H₂S) is an important signaling molecule in mammals, but its role in Mtb physiology is unclear. We have previously shown that exogenous H₂S can modulate expression of genes in the Dos dormancy regulon via an unknown mechanism(s). Here, we test the hypothesis that Mtb senses and responds to H₂S via the DosS/T/R system. Using UV-Vis and EPR spectroscopy, we show that H₂S binds directly to the ferric (Fe³⁺) heme of DosS (K_D^app = 5.30 μM) but not the ferrous (Fe²⁺) form. No interaction with DosT(Fe²⁺-O

SUBMITTER: Sevalkar RR 

PROVIDER: S-EPMC9062744 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature