Structure-function analysis for the hydroxylation of Δ4 C21-steroids by the myxobacterial CYP260B1

FEBS Lett. 2016 Jun;590(12):1838-51. doi: 10.1002/1873-3468.12217. Epub 2016 Jun 3.


Myxobacterial CYP260B1 from Sorangium cellulosum was heterologously expressed in Escherichia coli and purified. The in vitro conversion of a small focused substrate library comprised of Δ4 C21-steroids and steroidal drugs using surrogate bovine redox partners shows that CYP260B1 is a novel steroid hydroxylase. CYP260B1 performs the regio- and stereoselective hydroxylation of the glucocorticoid cortodoxone (RSS) to produce 6β-OH-RSS. The substrate-free crystal structure of CYP260B1 (PDB 5HIW) was resolved. Docking of the tested ligands into the crystal structure suggested that the C17 hydroxy moiety and the presence of either a keto or a hydroxy group at C11 determine the selectivity of hydroxylation.

Keywords: CYP260B1; Sorangium cellulosum; steroid.

Publication types

  • Letter

MeSH terms

  • Animals
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Cattle
  • Cortodoxone / chemistry*
  • Cortodoxone / metabolism
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Hydroxylation
  • Molecular Docking Simulation
  • Myxococcales / enzymology*
  • Myxococcales / genetics
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Steroid Hydroxylases / chemistry*
  • Steroid Hydroxylases / genetics
  • Steroid Hydroxylases / metabolism
  • Structure-Activity Relationship


  • Bacterial Proteins
  • Recombinant Proteins
  • Steroid Hydroxylases
  • Cortodoxone