K. Zito et al., LEAD-CATALYZED CLEAVAGE OF RIBONUCLEASE-P RNA AS A PROBE FOR INTEGRITY OF TERTIARY STRUCTURE, Nucleic acids research, 21(25), 1993, pp. 5916-5920
Pb2+-catalyzed cleavage of RNA has been shown previously to be a usefu
l probe for tertiary structure. In the present study, Pb2+ cleavage pa
tterns were identified for ribonuclease P RNAs from three phylogenetic
ally disparate organisms, Escherichia coli, Chromatiom vinosum, Bacill
us sobtilis, and for E.coli RNase P RNAs that had been altered by dele
tions. Each of the native RNAs undergoes cleavage at several sites in
the core structure that is common to all bacterial RNase P RNAs. Ail t
he cleavages occur in non-paired regions of the secondary structure mo
dels of the RNAs, in regions likely to be involved in tertiary interac
tions. Two cleavage sites occur at homologous positions in all the nat
ive RNAs, regardless of sequence variation, suggesting common tertiary
structural features. The Pb2+ cleavage sites in four deletion mutants
of E.coli RNase P RNA differed from the native pattern, indicating al
terations in the tertiary structures of the mutant RNAs. This conclusi
on is consistent with previously characterized properties of the mutan
t RNAs. The Pb2+ cleavage assay is thus a useful probe to reveal alter
ation of tertiary structure in RNase P RNA.