Essential role of the Arg112 residue of cytochrome P450cam for electron transfer from reduced putidaredoxin

Hideo Koga*, Yasuhiro Sagara, Tsuyoshi Yaoi, Mitsushi Tsujimura, Kazuhide Nakamura, Kazuhisa Sekimizu, Ryu Makino, Hideo Shimada, Yuzuru Ishimura, Kei Yura, Mitiko Go, Masamichi Ikeguchi, Tadao Horiuchi

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Citations (Scopus)


Cytochrome P450cam (CYP101) of Pseudomonas putida PpGl in which Arg112 is substituted by Cys was isolated by in vitro random mutagenesis of the camC gene DNA coding for P450cam. The absorption spectra of the purified mutant enzyme were similar to those of the wild type enzyme, but its substrate-dependent NADH oxidation activity in the presence of putidaredoxin (Pd) and putidaredoxin reductase (PdR) was extremely low. The rate constant of electron transfer from reduced Pd to the heme of the mutant P450cam, measured on an anaerobic stopped flow apparatus, was 1 400 of that of the wild type enzyme and the dissociation constant of the mutant P450cam for oxidized Pd was several fold higher than that of the wild type enzyme. A considerable decrease in mid-point potential of the mutant enzyme was also noted. We conclude that Arg112, which is located on the surface of the P450cam molecule and hydrogen-bonded to one of the heme propionate chains, plays an essential role in the electron transfer from Pd.

Original languageEnglish
Pages (from-to)109-113
Number of pages5
JournalFEBS Letters
Issue number1-2
Publication statusPublished - 1993 Sept 27
Externally publishedYes


  • Amino acid substitution
  • Binding of P450cam with putidaredoxin
  • Cytochrome P450cam
  • Electron transfer
  • Putidaredoxin
  • Random mutagenesis

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology


Dive into the research topics of 'Essential role of the Arg112 residue of cytochrome P450cam for electron transfer from reduced putidaredoxin'. Together they form a unique fingerprint.

Cite this