FIG. 2.
Organizational structure of 16S-23S rRNA ITS found in E. amylovora and E. pyrifoliae. Six rRNA operons were sequenced from each strain. The organizational structure of the spacers is indicated graphically. Regions C1, C2, and C3 are conserved regions of 58 to 60 bp, 98 to 99 bp, and 20 bp, respectively; region V is a variable 25-bp sequence; and region O is an optional 139-bp sequence. All X alleles contain a tRNAGlu gene, and all Y alleles contain tandem tRNAIle and tRNAAla genes. X+ indicates alleles that contain tRNAGlu genes with an XbaI restriction site. The number of copies of each allele is listed for each strain along with the primer (from 1 = 5SFlank1 to 6 = 5SFlank6) paired with the primer SpacerF, used to amplify the alleles given in parentheses.