The cytochrome P450 gene family CYP157 does not contain EXXR in the K-helix reducing the absolute conserved P450 residues to a single cysteine

Sanjeewa Rupasinghe, Mary A Schuler, Norio Kagawa, Hang Yuan, Li Lei, Bin Zhao, Steven L. Kelly, Michael R. Waterman, David C. Lamb

Research output: Contribution to journalArticle


In this work, we have spectroscopically characterised CYP157C1 from Streptomyces coelicolor A3(2) which has the motif E 297 QSLW 301 rather than the invariant EXXR motif in the P450 K-helix. Site-directed mutagenesis of native E 297 QSLW 301 in CYP157C1 to E 297 ESLR 301 or E 297 QSRW 301 both containing standard EXXR motifs produced cytochrome P420 proteins thought to be inactive forms of P450 even though wild type CYP157C1 has the spectral properties of a normal P450. These results indicate that the EXXR motif is not required in all CYP tertiary architectures and only a single cysteine residue, which coordinates as the fifth thiolate ligand to the P450 haem iron, is invariant in all CYPs structures.

Original languageEnglish (US)
Pages (from-to)6338-6342
Number of pages5
JournalFEBS Letters
Issue number27
StatePublished - Nov 27 2006



  • Cytochrome P450
  • Protein folding
  • Site-directed mutagenesis
  • Streptomyces

ASJC Scopus subject areas

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

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