Table 1.

Known tetracycline resistance determinantsa

Tet determinant (or gene, if no determi-nant name was given)MechanismGenBank accession no.Refer-ence
Tet AEffluxX0000633
Tet BEffluxJ0183011
Tet CEffluxJ0174923
Tet DEffluxX658762
Tet EEffluxL069401
Tet FEfflux (ineffective?)Unsequenced22, 30
Tet GEffluxS5243734
Tet HEffluxU0079210
Tet IEfflux (?)Unsequenced25
Tet JEffluxAF03899316
Tet KEffluxM1621720
Tet L (plasmid)bEffluxM1103613
Tet L (chromosomal)bEffluxX0803426
Tet MRibosomal protectionX0438817
(Tet N)(Withdrawn)12
Tet ORibosomal protectionM18896c28
Tet PEfflux, ribosomal pro-tection (two genes)L2080027
Tet QRibosomal protectionX5871719
Tet SRibosomal protectionL097564
Tet TRibosomal protectionL425445
Tet UUnknownU0191724
Tet VEffluxAF0303447;1)
Tet WRibosomal protectionAJ2227693
Tet XModificationM3769929
Tet YEffluxAF07099932
Tet ZEffluxAF12100031
otrARibosomal protectionX534019
otrBEffluxAF07990018
otrCUnknownUnsequenced21, 25
tcr3(tcrC)EffluxD382156
tetRibosomal protectionM740498
Tet 30 [originally unnamed determinant; protein is 46% identical to TetA(A)]EffluxAF090987 (wild type)15
  • a In most cases, we cite the first publication to report the sequence for one or both genes of a determinant. In cases where major (but not minor) errors were later corrected, we cite the later publication. The sequences of many variants of some determinants (particularly Tet L and Tet M) are available but are not given here. Four different unnamed and unsequenced but presumed ribosomal protection determinants (5) are not included.

  • b The proteins encoded by these two Tet L determinants are only 81% identical.

  • c The original sequence is not available electronically, so another is substituted.