CHARACTERIZATION OF THE BORRELIA-BURGDORFERI RNASE-P RNA GENE REVEALSA NOVEL TERTIARY INTERACTION

Characterization of the RNase P RNA gene derived from Borrelia burgdor feri reveals covariation of the conserved nucleotides at positions cor responding to nucleotides 128 and 230 in Escherichia coli RNase P RNA (M1 RNA). Single base substitutions at either of these positions in M1 RNA resulted in a lack of complementation of the temperature-sensitiv e phenotype associated with rnpA49 in vivo whereas complementation was observed for the double mutant M1 RNA or wild-type M1 RNA. Our in vit ro data showed that M1 RNA harbouring a substitution at 128 or 230 cle aved a tRNA precursor both in the absence and presence of C5 with redu ced efficiency compared to the wild-type and the double mutant M1 RNA, We conclude that the nucleotides at positions 128 and 230 establish a long-range tertiary interaction in RNase P RNA. Our data also suggest that this interaction together with the identity of the nucleotide at position 230 is important for Pb2+ induced cleavage at specific posit ions in M1 RNA.