Fig. 1.

Schematic structures of RNase P RNAs. (A) Universal consensus secondary structure of bacterial, archaeal, and eukaryal nuclear RNase P RNAs [25]. Gray indicates variable structures connecting conserved regions. Helices P1–P12 [144] and conserved sequence regions CR I–V [145] are indicated. Structural elements absent only in single, minor phylogenetic groups are included: P12, absent in M. genitalium[34]; P11, P12, CR II, and CR III, absent in P. aerophilum[43]. (B) Secondary structure of S. cerevisiae mtRNase P RNA (Rpm1r) [65].