Table 4.

Consensus sequences of conserved motifs in transporters of the MFS, SMR, and RND families

MotifConsensus sequenceaLocation
MFS, both 12- and 14-TMS cluster
 AG x L a D r x G r k x x (x) lLoop between TMS 2 and 3
 Bl x x x R x x q G x g a aTMS 4
 Cg x x x G P x x G G x lEnd of TMS 5
MFS, 12-TMS cluster
 D2l g x x x x x P v x PEnd of TMS 1
 GG x x x G P LEnd of TMS 11
MFS, 14-TMS cluster
 D1l D x T v x n v A l PEnd of TMS 1
 ED x x G x x LTMS 7
 Fl g x x x G x a v x g x lTMS 13
 HW x w x F l l N v P i gTMS 6
SMR family
 AW i x l v i A i l l E VTMS 1
 BK x s e G F t r l x P SLoop between TMS 1 and 2
 CP v G t A Y A v W t G l GStart of TMS 3
RND family
 AG x s x v T v x F x x g t D x x x A q v q V q n k L q x A x p x L P x x V q x q g x x v x kLoop between TMS 1 and 2
 Ba l v l s a V F l P m a f f g G x t G x i y r q f s i T x v s A m a l S v x v a l t l t P A l c ATMS 6
 Cx x x G k x l x e A x x x a a x x R L R P l L M T s L a f i l G v l P l a i a t G x A G aTMS 11
 DS i N t l T l f g l v l a i G L l v D D A l V v V E N v e R v l a eTMS 4
  • a The motifs were identified by alignment of amino acid sequences (190, 191). The consensus sequences of the motifs are displayed as follows: x, any amino acid; capital letters, amino acid occurs in >70% of the examined sequences; lowercase letters, amino acid occurs in >40%; (x), amino acid not always present.