FIG. 1.

Construction of S. meliloti Rm11466 by transposon replacement. A 4-kb DNA fragment containing the lrpL and acdS genes from R. leguminosarum bv. viciae 128C53K was inserted into the BamHI site of transposon Tn5 in pGS220 to construct pWM3. pWM3 is suicidal after being introduced into S. meliloti Rm5356. After double crossover between the IS50 regions of the two transposons, Tn5-233 and Tn5-acd, the neomycin resistance gene, leucine-responsive regulatory-like gene (lrpL), and the ACC deaminase structural gene (acdS) were inserted into megaplasmid pRmeSU47b in S. meliloti Rm5356. The resulting variant was named Rm11466. Restriction sites: B, BamHI; E, EcoRI; H, HindIII. There are multiple HindIII sites in Tn5-233 and Tn5-acd, but only the locations of the sites inside the IS50 regions are shown on the restriction map.