bb0219 is cotranscribed with bb0220–bb0224. (A) Schematic representation of the putative bb0219–bb0224 operon in Bb. (B) Results from RT-PCR. Lane 1, molecular weight markers; lane 2, primer pair a1 and a2 in ordinary PCR using genomic DNA as template; lane 3, primer pair a1 and a2 in ordinary PCR using RNA as template (no RT control); lane 4, primer pair a1 and a2; lane 5, primer pair a3 and b1; lane 6, primer pair b2 and c1; lane 7, primer pair c2 and d1; lane 8, primer pair d2 and e1; lane 9, primer pair e2 and f1; and lane 10, primer pair f2 and g1.