biostudies-literatureUnknownApiche EANIGMS NIH HHSDosT and DosS are heme-based kinases involved in sensing and signaling O₂ tension in the microenvironment of <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>). Under conditions of low O₂, they activate >50 dormancy-related genes and play a pivotal role in the induction of dormancy and associated drug resistance during tuberculosis infection. In this work, we reexamine the O₂ binding affinities of DosT and DosS to show that their equilibrium dissociation constants are 3.3±1 μM and 0.46±0.08 μM respectively, which are six to eight-fold stronger than what has been widely referred to in literature. Furthermore, stopped-flow kinetic studies reveal association and dissociation rate constants of 0.84 μM^-1s^-1 and 2.8 s^-1, respectively for DosT, and 7.2 μM^-1s^-1 and 3.3 s^-1, respectively for DosS. Remarkably, these tighter O₂ binding constants correlate with distinct stages of hypoxia-induced non-replicating persistence in the Wayne model of <i>Mtb</i>. This knowledge opens doors to deconvoluting the intricate interplay between hypoxia adaptation stages and the signal transduction capabilities of these important heme-based O₂ sensors.bioRxiv : the preprint server for biology2024.02.26.582189https://www.ebi.ac.uk/biostudies/studies/S-EPMC10925234biostudies-literatureOxygen affinities of DosT and DosS sensor kinases with implications for hypoxia adaptation in <i>Mycobacterium tuberculosis</i>.PMC10925234R35 GM138277Damodaran ARBhagi-Damodaran AYee EApiche EAfalseOxygen affinities of DosT and DosS sensor kinases with implications for hypoxia adaptation in <i>Mycobacterium tuberculosis</i>.DosT and DosS are heme-based kinases involved in sensing and signaling O₂ tension in the microenvironment of <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>). Under conditions of low O₂, they activate >50 dormancy-related genes and play a pivotal role in the induction of dormancy and associated drug resistance during tuberculosis infection. In this work, we reexamine the O₂ binding affinities of DosT and DosS to show that their equilibrium dissociation constants are 3.3±1 μM and 0.46±0.08 μM respectively, which are six to eight-fold stronger than what has been widely referred to in literature. Furthermore, stopped-flow kinetic studies reveal association and dissociation rate constants of 0.84 μM^-1s^-1 and 2.8 s^-1, respectively for DosT, and 7.2 μM^-1s^-1 and 3.3 s^-1, respectively for DosS. Remarkably, these tighter O₂ binding constants correlate with distinct stages of hypoxia-induced non-replicating persistence in the Wayne model of <i>Mtb</i>. This knowledge opens doors to deconvoluting the intricate interplay between hypoxia adaptation stages and the signal transduction capabilities of these important heme-based O₂ sensors.2024-01-01T00:00:00Z2024 Feb2026-05-29T03:18:00.356Z2025-04-07T07:07:39.928ZS-EPMC109252343846419510.1101/2024.02.26.582189