Homology of the flanking regions of the alpha C and alpha-like protein genes. The 13.7-kb insert of pJMS23, exclusive of the previously sequenced bca gene, was sequenced. pJMS23 originally was constructed from strain A909 (7). ORFs are designated by solid arrows. Numbers above the solid arrows correspond to the ORF numbers listed in Table 1. bca is the gene encoding the alpha C protein. PCR amplicons using primer pairs (N-1, N-2, C-1, C-2) constructed according to sequence from pJMS23 are designated by dashed lines with arrow ends at the top of the figure. Maps of the regions flanking the alpha-like protein genes in strains BM-110 (protein Rib), CJB-110 (Alp2), JM9–130013 (Alp3), and 18RS21 (protein nonexpresser) were constructed by using PCR and partial sequencing (see text) and are designated by solid lines below the pJMS23 sequence. Inverted hatches in the maps refer to insertions. Open rectangles indicate deletions. Dotted lines within the maps indicate regions that have not been analyzed. IS1381 and IS1191, insertion sequences (see text).