The RNA-protein subunit assembly of nuclear RNase P was investigated by specific isolation and characterization of the precursor and mature forms of RNase P using an RNA affinity ligand. Pre-RNase P was as active in pre-tRNA cleavage as mature RNase P, although it contained only seven of the nine proteins found in mature RNase R Pop3p and Rpr2p were not required for maturation of the RPR1 RNA subunit and virtually absent from pre-RNase P, implying that they are dispensable for pre-tRNA substrate recognition and cleavage. The RNase P subunit assembly is likely to occur in the nucleolus, where both precursor and mature forms of RNase P RNA are primarily localized. The results provide insight into assembly of nuclear RNase P, and suggest pre-tRNA substrate recognition is largely determined by the RNA subunit.
An active precursor in assembly of yeast nuclear ribonuclease P
Srisawat, C.; Houser-Scott, F.; Bertrand, E.; Xiao, S. H.; Singer, R. H.; Engelke, D. R.
Rna-a Publication of the Rna Society
2002-10 / vol 8 / pages 1348-1360
saccharomyces-cerevisiae; ribosomal-rna; affinity tags; catalytic activity; escherichia-coli; essential protein subunit; mrp; multiple sequence alignment; pop3; ribonucleoprotein complexes; rna secondary structure; rnase p; rpr1; rpr2