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Publication Abstract from PubMed

Bacteria modulate essential phenotypes in response to external signals such as the availability of molecular oxygen (O(2)). A class of direct O(2)-sensing heme proteins, globin coupled sensors, have been implicated in O(2)-dependent regulation of pathogenic phenotypes including biofilm formation, motility, and virulence. While cooperative O(2) binding is well known in both mammalian and prokaryotic hemoglobins, cooperative ligand binding previously has not been observed in bacterial sensor globins. This study explores the O(2)-dependent allosteric communication between globin domains in the globin-coupled sensor protein from Pectobacterium carotovorum (PccGCS) through equilibrium O(2) binding measurements, X-ray crystallography, resonance Raman spectroscopy, and hydrogen-deuterium exchange mass spectrometry. Based on these experiments, we propose a model of allosteric regulation of O(2) binding that is directed by subtle changes in distal heme pocket protein conformation and transduced through dynamics of helices at the dimer interface of the PccGCS sensor globin. Together this work identifies cooperative ligand binding in a family of bacterial heme proteins, which could allow the bacteria to more robustly respond to small changes in O(2) levels. Furthermore, this work highlights the importance of heme pocket residues in transducing the O(2) binding event within the dimer and suggests a pathway for signal transduction in dimeric myoglobin-like sensor proteins.

Cooperative Ligand Binding in a Bacterial Heme-Based Oxygen Sensor.,Hoque NJ, Pope SR, Venkatakrishnan V, Olori DO, Brady NA, Patterson DC, Anand GS, Liu Y, Boal AK, Weinert EE J Biol Chem. 2025 Dec 8:111025. doi: 10.1016/j.jbc.2025.111025. PMID:41371339^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.