Site-directed mutagenesis studies of selected motif and charged residues and of cysteines of the multifunctional tetracycline efflux protein Tet(L)

J Bacteriol. 2002 Mar;184(6):1796-800. doi: 10.1128/JB.184.6.1796-1800.2002.

Abstract

All of the transmembrane glutamates of Tet(L) are essential for tetracycline (TET) resistance, and E397 has been shown to be essential for all catalytic modes, i.e., TET-Me(2+) and Na(+) efflux and K(+) uptake. Loop residues D74 and G70 are essential for TET flux but not for Na(+) or K(+) flux. A cysteineless Tet(L) protein exhibits all activities.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antiporters / chemistry
  • Antiporters / genetics*
  • Antiporters / metabolism
  • Cysteine / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins*
  • Glutamates / metabolism
  • Ion Transport
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Mutagenesis, Site-Directed
  • Potassium / metabolism
  • Sodium / metabolism
  • Tetracycline Resistance / genetics

Substances

  • Antiporters
  • Escherichia coli Proteins
  • Glutamates
  • Membrane Proteins
  • Tet(L) protein, E coli
  • Sodium
  • Cysteine
  • Potassium