α-Methyl Acyl CoA Racemase Provides Mycobacterium tuberculosis Catabolic Access to Cholesterol Esters

Biochemistry. 2015 Sep 22;54(37):5669-72. doi: 10.1021/acs.biochem.5b00911. Epub 2015 Sep 11.

Abstract

Metabolism of cholesterol by Mycobacterium tuberculosis (Mtb) contributes to its pathogenesis. We show that ChsE4-ChsE5 (Rv3504/Rv3505) specifically catalyzes dehydrogenation of the (25S)-3-oxo-cholest-4-en-26-oyl-CoA diastereomer in cholesterol side chain β-oxidation. Thus, a dichotomy between the supply of both 25R and 25S metabolic precursors by upstream cytochrome P450s and the substrate stereospecificity of ChsE4-ChsE5 exists. We reconcile the dilemma of 25R metabolite production by demonstrating that mycobacterial MCR (Rv1143) can efficiently epimerize C25 diastereomers of 3-oxo-cholest-4-en-26-oyl-CoA. Our data suggest that cholesterol and cholesterol ester precursors can converge into a single catabolic pathway, thus widening the metabolic niche in which Mtb survives.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acyl Coenzyme A / chemistry*
  • Acyl Coenzyme A / metabolism
  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism
  • Cholesterol / analogs & derivatives*
  • Cholesterol / chemistry
  • Cholesterol / metabolism
  • Cholesterol Esters / chemistry*
  • Cholesterol Esters / metabolism
  • Kinetics
  • Metabolic Networks and Pathways
  • Mycobacterium tuberculosis / metabolism*
  • Oxidation-Reduction
  • Racemases and Epimerases / chemistry*
  • Racemases and Epimerases / metabolism
  • Stereoisomerism

Substances

  • Acyl Coenzyme A
  • Bacterial Proteins
  • Cholesterol Esters
  • Cholesterol
  • Racemases and Epimerases
  • alpha-methylacyl-CoA racemase