Mycobacterium smegmatis MSMEG_3705 encodes a selective major facilitator superfamily efflux pump with multiple roles

Curr Microbiol. 2015 Jun;70(6):801-9. doi: 10.1007/s00284-015-0783-0. Epub 2015 Feb 20.

Abstract

Mycobacterium smegmatis mc(2)155 MSMEG_3705 gene was annotated to encode a transporter protein that contains 12 alpha-helical transmembrane domains. We predicted MSMEG_3705 encoding a major facilitator superfamily (MFS) member. To confirm the prediction, the M. smegmatis mc(2)155 MSMEG_3705 gene was deleted. The MSMEG_3705 deletion mutant strain M. smegmatis mc(2)155 ∆MSMEG_3705 was more sensitive to capreomycin. Moreover, M. smegmatis mc(2)155 ∆MSMEG_3705 strain accumulated more ethidium bromide intracellular than wild-type M. smegmatis mc(2)155. Quite unexpectedly, M. smegmatis mc(2)155 ∆MSMEG_3705 grew faster than the wild-type M. smegmatis mc(2)155. The upregulation of the expression of MSMEG_3706, a gene encoding isocitrate lyase downstream MSMEG_3705, in the deletion mutant, might underlie such faster growth in the mutant. The study showed that MSMEG_3705 encodes a genuine MFS member and plays significant role in bacterial growth and antibiotics resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antitubercular Agents / metabolism
  • Biological Transport, Active*
  • Capreomycin / metabolism
  • Drug Resistance, Bacterial
  • Ethidium / metabolism
  • Gene Deletion
  • Membrane Transport Proteins / genetics*
  • Membrane Transport Proteins / metabolism*
  • Mycobacterium smegmatis / drug effects
  • Mycobacterium smegmatis / genetics*
  • Mycobacterium smegmatis / growth & development
  • Mycobacterium smegmatis / metabolism*

Substances

  • Antitubercular Agents
  • Membrane Transport Proteins
  • Capreomycin
  • Ethidium