Figure 1.

(A) Physical and genetic map of the pROX341 plasmid containing the bet genes of S. meliloti. The insertions with the allele number are shown by arrowheads below the map. The arrowhead content indicates a minus (solid), leaky (gray), or wild-type (open) choline growth phenotype. The position of the two mosaic elements SmbetIC and SmbetBA is indicated by shaded boxes. Restriction sites shown are ApaI (A), BglII (B), EcoRI (E), HindIII (H), PstI (P), and SmaI (S). (B) Sequence alignment of the four mosaic elements and the four palindromes that were identified in Rhizobiaceae. The numbers on the left show the position of the elements within the published sequences. The conserved left and right domains are boxed, and the three palindromes (A, B, and C) are indicated by solid arrows. The flanking left (L) and right (R) heptamers are shown by open arrows. Only the 5-bp flanking sequence of the central region is given with the number of remaining nucleotides (N). Sm, S. meliloti; Rlt, R. leguminosarum bv. trifolii; Sf, S. fredii; Rt, R. tropicii; Bj, B. japonicum.