Figure 1.

Secondary structures of the M. thermoautotrophicum strain ΔH, M. jannaschii, and Escherichia coli RNase P RNAs (refs. 11 and 12, and J.K.H., E.S.H., and J.W.B., unpublished data). Helices are numbered P1–P18 as described (24). Helices P4 and P6 are shown with lines and brackets. The 5′ and 3′ ends of the native archaeal RNAs were determined by primer extension and nuclease S1 protection. Additional RNase P RNA sequences and structures are available on the Ribonuclease P database at www.mbio.ncsu.edu/RNaseP/home.html (25).