Characterization of a Cobalt-Substituted Globin-Coupled Oxygen Sensor Histidine Kinase from Anaeromyxobacter sp. Fw109-5: Insights into Catalytic Regulation by Its Heme Coordination Structure.

ABSTRACT: Heme-based gas sensors are an emerging class of heme proteins. AfGcHK, a globin-coupled histidine kinase from Anaeromyxobacter sp. Fw109-5, is an oxygen sensor enzyme in which oxygen binding to Fe(II) heme in the globin sensor domain substantially enhances its autophosphorylation activity. Here, we reconstituted AfGcHK with cobalt protoporphyrin IX (Co-AfGcHK) in place of heme (Fe-AfGcHK) and characterized the spectral and catalytic properties of the full-length proteins. Spectroscopic analyses indicated that Co(III) and Co(II)-O₂ complexes were in a 6-coordinated low-spin state in Co-AfGcHK, like Fe(III) and Fe(II)-O₂ complexes of Fe-AfGcHK. Although both Fe(II) and Co(II) complexes were in a 5-coordinated state, Fe(II

SUBMITTER: Kitanishi K 

PROVIDER: S-EPMC8697598 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature