Identification of two important heme site residues (cysteine 75 and histidine 77) in CooA, the CO-sensing transcription factor of Rhodospirillum rubrum.

@article{Shelver1999IdentificationOT,
  title={Identification of two important heme site residues (cysteine 75 and histidine 77) in CooA, the CO-sensing transcription factor of Rhodospirillum rubrum.},
  author={D Shelver and Marc V. Thorsteinsson and Robert L. Kerby and Seon Yong Chung and Gary P. Roberts and Mark F. Reynolds and Ryan B Parks and Judith N Burstyn},
  journal={Biochemistry},
  year={1999},
  volume={38 9},
  pages={2669-78}
}
The CO-sensing mechanism of the transcription factor CooA from Rhodospirillum rubrum was studied through a systematic mutational analysis of potential heme ligands. Previous electron paramagnetic resonance (EPR) spectroscopic studies on wild-type CooA suggested that oxidized (FeIII) CooA contains a low-spin heme with a thiolate ligand, presumably a cysteine, bound to its heme iron. In the present report, electronic absorption and EPR analysis of various substitutions at Cys residues establish… CONTINUE READING