P-cresol and 3,5-xylenol methylhydroxylases in Pseudomonas putida N.C.I.B. 9896

Biochem J. 1978 Nov 1;175(2):649-58. doi: 10.1042/bj1750649.


Pseudomonas putida N.C.I.B. 9869, when grown on 3,5-xylenol, hydroxylates the methyl groups on 3,5-xylenol and on p-cresol by two different enzymes. 3,5-Xylenol methylhydroxylase, studied only in relatively crude extracts, requires NADH, is not active with p-cresol and is inhibited by cyanide, but not by CO. The p-cresol methylhydroxylase requires an electron acceptor and will act under anaerobic conditions. It was purified and is a flavocytochrome c of mol.wt. approx. 114,000 consisting of two subunits of equal size. The enzyme catalyses the hydroxylation of p-cresol (Km 16 micron) and the further oxidation of product, p-hydroxybenzyl alcohol (Km 27 micron) to p-hydroxybenzaldehyde. A different p-cresol methylhydroxylase of the flavocytochrome c type is induced by growth on p-cresol. It too was purified and has mol.wt. approx. 100,000, and again consisted of two equal-size subunits. The Km for p=cresol 3.6 micron and for p=hydroxybenzyl alcohol, 15 micron.

MeSH terms

  • Cresols
  • Electrophoresis, Polyacrylamide Gel
  • Flavins / analysis
  • Kinetics
  • Mixed Function Oxygenases / isolation & purification
  • Mixed Function Oxygenases / metabolism*
  • Oxidation-Reduction
  • Pseudomonas / enzymology*
  • Substrate Specificity
  • Xylenes


  • Cresols
  • Flavins
  • Xylenes
  • Mixed Function Oxygenases
  • 3,5-xylenol methylhydroxylase
  • 3,5-xylenol