Consensus diagrams of novel putative RNA structures and individual examples used for transcriptomic analysis. Novel regulatory RNAs we have identified upstream of the rpsO operon. H0 helices were originally predicted by comparative genomics, but not supported by transcriptomic analysis and therefore are unlikely to be biologically relevant. A: RNA originating from Alphaproteobacteria, B: RNA originating from Actinobacteria, and C: RNA originating from Chlamydia. D: Alphaproteobacterial RNA example originating from Rhodobacter spaeroides (NC_011963.1) showing putative transcription start site determined from analysis of RNA-seq reads (Additional file 4: Figure S1A) . E: Actinobacterial RNA example originating from Mycobacterium tuberculosis (NC_000962.3) showing putative transcription start site determined from analysis of RNA-seq reads (Additional file 4: Figure S1B). F: Chlamydia RNA example originating from Chlamydia trachomatis with previously determined transcription start site (NC_010280.1/275170) .