A riboswitch regulates expression of the coenzyme B12-independent methionine synthase in Mycobacterium tuberculosis: implications for differential methionine synthase function in strains H37Rv and CDC1551

J Bacteriol. 2007 May;189(9):3655-9. doi: 10.1128/JB.00040-07. Epub 2007 Feb 16.

Abstract

We observed vitamin B(12)-mediated growth inhibition of Mycobacterium tuberculosis strain CDC1551. The B(12) sensitivity was mapped to a polymorphism in metH, encoding a coenzyme B(12)-dependent methionine synthase. Vitamin B(12)-resistant suppressor mutants of CDC1551 containing mutations in a B(12) riboswitch upstream of the metE gene, which encodes a B(12)-independent methionine synthase, were isolated. Expression analysis confirmed that the B(12) riboswitch is a transcriptional regulator of metE in M. tuberculosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / biosynthesis*
  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / genetics
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics
  • Cobamides / pharmacology
  • Gene Expression Regulation, Bacterial*
  • Growth Inhibitors / pharmacology
  • Molecular Structure
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / growth & development
  • Mycobacterium tuberculosis / physiology*
  • Nucleic Acid Conformation
  • RNA, Bacterial / biosynthesis
  • RNA, Messenger / biosynthesis
  • Suppression, Genetic
  • Transcription, Genetic

Substances

  • Bacterial Proteins
  • Cobamides
  • Growth Inhibitors
  • RNA, Bacterial
  • RNA, Messenger
  • 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase