Figure 1. Transcriptional analysis of avashort und avalong genes from A. variabilis. (A) Northern analysis of RNA isolated from A. variabilis kept at 23 °C or heat shocked to 40 °C for 1 h. Avashort and avalong mRNA was detected with specific digoxygenine-labeled RNA probes. (B) Sequence alignment of avashort/alrshort and avalong/alrlong. Sequence alignment of the small heat shock gene promoter regions and 5′UTRs from A. variabilis ATCC 29413 (avashort, avalong) and the homologous genes (alrshort, alrlong) from Nostoc PCC 7120 performed using ClustalW2.84,85 Similarity is indicated by asterisks. For avashort and avalong, promoter sequences were computed with BPROM from the softberry webserver, transcriptional start sites (*) were determined by 5′RACE. For Nostoc, start sites were published before.3 Both sequence alignments reveal high similarity. Promoter sequences (-35, -10), transcriptional start sites (*), Shine-Dalgarno sequence (SD), and ATG start codon are depicted.