Genetic organization of the Hklep/Rrlep two-component system in Leptospira spp. (A) Organization of hklep/rrlep genes in L. biflexa. The two-component system genes are shaded in black. Gene labels are given for each surrounding genes (white). The arrow indicates the insertion site of the Himar1 transposon. (B) Schematic representation of the heme biosynthesis genes in L. interrogans. The hemACDBLENYH genes are shaded in grey. The homologous two-component system genes, hklep and rrlep, are shaded in black. The L. biflexa Hklep and Rrlep proteins share 66 % and 69 % similarities with L. interrogans LB014 and LB015, respectively.