Inventory and analysis of the protein subunits of the ribonucleases P and MRP provides further evidence of homology between the yeast and human enzymes.
The RNases P and MRP are involved in tRNA and rRNA processing, respectively. Both enzymes in eukaryotes are composed of an RNA molecule and 9-12 protein subunits. Most of the protein subunits are shared between RNases P and MRP. We have here performed a computational analysis of the protein subunits in a broad range of eukaryotic organisms using profile-based searches and phylogenetic methods. A number of novel homologues were identified, giving rise to a more complete inventory of RNase P/MRP proteins. We present evidence of a relationship between fungal Pop8 and the protein subunit families Rpp14/Pop5 as well as between fungal Pop6 and metazoan Rpp25. These relationships further emphasize a structural and functional similarity between the yeast and human P/MRP complexes. We have also identified novel P and MRP RNAs and analysis of all available sequences revealed a K-turn motif in a large number of these RNAs. We suggest that this motif is a binding site for the Pop3/Rpp38 proteins and we discuss other structural features of the RNA subunit and possible relationships to the protein subunit repertoire.
Rosenblad
Magnus Alm
MA
Department of Medical Biochemistry, Institute of Biomedicine, Goteborg University, Box 413 SE-405 30 Goteborg, Sweden.
López
Marcela Dávila
MD
Piccinelli
Paul
P
Samuelsson
Tore
T
D000595:Amino Acid Sequence; D004722:Endoribonucleases / Q000737:chemistry / Q000145:classification* / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000145:classification* / Q000235:genetics; D023281:Genomics; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D021122:Protein Subunits / Q000737:chemistry / Q000145:classification* / Q000235:genetics; D043262:Ribonuclease P / Q000737:chemistry / Q000145:classification* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D017386:Sequence Homology, Amino Acid; D015003:Yeasts / Q000201:enzymology*
D005656:Fungal Proteins; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; D004722:Endoribonucleases; C058330:mitochondrial RNA-processing endoribonuclease; D043262:Ribonuclease P