TABLE 2.

Classification and amino acid identities of some putative drug efflux proteins of M. tuberculosis H37Rv and M. smegmatis mc2155 and the mRNA expression of the M. smegmatis efflux genes measured by RT-PCR

Gene(s) of M. tuberculosisGene(s) of M. smegmatisFamilyaAmino acid residue identity (%)b (M. tuberculosis vs M. smegmatis)mRNA expression in M. smegmatisc
Rv1145-Rv1146d4208498-6201eRND62+
Rv12504074929-3495MFS63+
Rv1258c (tap)4057327-7998MFS67+
Rv1410c (P55)2073408-1882MFS69++
Rv16342814796-3420MFS64+
Rv1819c3395875-7779ABC63++
Rv18772555505-2748MFS58+
Rv2136c3203468-2646ABC73++
Rv2836c1641611-2909MATE74+
Rv2846c (efpA)1629942-31402MFS81±
Rv29941393778-2456MFS54+
Rv3065 (mmr, emrE)2666199-373SMR40+
Absent lfrA f MFSNA±
  • a The classification is based on the published literature (2, 8, 12, 13, 14, 33) and information online at http://www.membranetransport.org and http://www.sanger.ac.uk/Projects/M_tuberculosis/ . RND, resistance-nodulation-cell division family; MATE, multidrug and toxic extrusion family.

  • b The percent identity figures are based on BLAST alignment without the use of a filter.

  • c The mRNA expression levels assessed by RT-PCR were semiquantitatively determined to be strong (++), medium (+), and weak (±).

  • d The homologues of these two M. tuberculosis genes (i.e., Rv1145 and Rv1146) belong to a single gene in M. smegmatis.

  • e Nucleotide residue numbers in the M. smegmatis genome database at The Institute for Genomic Research.

  • f Homologues of the M. smegmatis lfrA gene were not identified in the M. tuberculosis genome. NA, not applicable.