Mapping of 41 chemotaxis, flagellar and motility genes to a single region of the Sinorhizobium meliloti chromosome

Three previously identified gene clusters that contain chemotaxis (che), fl agellar (fla) and motility (mot) genes of Sinorhizobium meliloti (formerly Rhizobium meliloti) were mapped to a contiguous 45-kb region of the S. meli loti RU11/001 genome by pulsed-field gel electrophoresis (PFGE) in combinat ion with Southern hybridization. The entire region was cloned and sequenced . The map combines 32 che, fla (flg, flh, fli) and mot genes and nine new o pen reading frames that probably encode taxis-related functions as well. It is concluded that between 80 and 90% of the genes responsible for chemotax is and motility are located in a single region of the S. meliloti chromosom e near the his-39 marker. (C) 1998 Elsevier Science B.V. All rights reserve d.