Fig. 1
Predicted structures of KfrA proteins from R751 and RA3 plasmids and organization of kfrAp regions. KfrAR751 (IncP-1β) (a) and KfrARA3 (IncU) (b) amino acid sequences predicted secondary structure visualized with POLYVIEW-2D server. Sequence regions corresponding to the HTH and coiled-coil domains are marked in blue and green, respectively. The secondary structure is shown below the sequence as red ribbons (helices) and blue bars (strands). c kfrAR751 promoter region with − 35 and − 10 motifs indicated in bold. Start codon and rbs – ribosome binding site for KfrA and binding sites for regulatory proteins are shown: OA- KorAR751 operator, OB- KorBR751 operator, OK- putative KfrA R751 operator. d kfrARA3 promoter region with − 35 and − 10 motifs indicated as above. Putative KfrA RA3 binding site (OK) of five 9 nt repeats is indicated by arrows