sRk48 and sRk52 from repetitive intergenic regions conserved among thermococcal genomes. (A) Detection of sRk48/sRk52 by Northern blot. Source of RNAs, markers and sR26 loading control are as indicated in Figure 1B. (B) Gene maps drawn to scale. Transcripts are specified in red along with the nature of their respective 5'end, (ppp) or (p) for tri- or mono-phosphate, respectively.