RPM1 Summary Help

Standard Name RPM1
Feature Type ncRNA
Description RNA component of mitochondrial RNase P; mitochondrial RNase P also contains the protein subunit Rpm2p; RNase P removes 5' extensions from mitochondrial tRNA precursors; RPM1 is conserved in bacteria, fungi, and protozoa (1, 2, 3 and see Summary Paragraph)
Name Description RNase P Mitochondrial
Chromosomal Location
ChrMito:85295 to 85777 | ORF Map | GBrowse
Gene Ontology Annotations All RPM1 GO evidence and references
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
sequence information
ChrMito:85295 to 85777 | ORF Map | GBrowse
This feature contains embedded feature(s): Q0297
Last Update Coordinates: 2003-12-02 | Sequence: 2003-12-02
Subfeature details
Most Recent Updates
Coordinates Sequence
Noncoding exon 1..483 85295..85777 2003-12-02 2003-12-02
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
External Links All Associated Seq | Search all NCBI (Entrez)
Primary SGDIDS000029023

RPM1 is a mitochondrial gene that encodes an RNA of about 450 nucleotides, also known as the 9S RNA (4, 5). It was originally identified as a locus on the mitochondrial genome that was required for removal of 5' leaders from mitochondrial tRNA precursors (6, 7). The RPM1 RNA comprises one subunit of the enzyme mitochondrial RNase P, which performs 5' processing of pre-tRNAs (2, 8); the other subunit is a protein encoded by the nuclear RPM2 gene (9). Rpm2p is required for the tRNA processing activity of the enzyme, and is also required for maturation of the RPM1 RNA, which does not have the normal 5' or 3' ends in a strain carrying a C-terminally truncated variant of Rpm2p (10).

RPM1 has similarity to the RNA subunits of two-subunit RNases P found in bacteria and protozoa (3, 11). It is conserved in the mitochondrial genomes of other yeasts, but its size varies widely. Some homologs are only about 140 nucleotides in length, suggesting that S. cerevisiae RPM1 may contain nonessential regions (1). As another indication that some regions may be dispensable, the RPM1 RNA becomes fragmented during purification of RNase P from mitochondria, but the enzyme containing RNA fragments remains active (11).

Three enzyme complexes involved in RNA processing are evolutionarily and physically related, and are easily confused with each other (see 12 and references therein). Mitochondrial RNase P is composed of the mitochondrially-encoded RPM1 RNA and the nuclear-encoded protein Rpm2p; it removes the 5' leaders from mitochondrial tRNA precursors. Nuclear RNase P, which removes the 5' leaders from cytoplasmic tRNA precursors, is composed of the RPR1 RNA subunit and Pop1p, Pop3p, Pop4p, Pop5p, Pop6p, Pop7p, Pop8p, Rpp1p, and Rpr2p. RNase MRP (RNase mitochondrial RNA processing) shares some subunits with nuclear RNase P: it is composed of an RNA subunit encoded by the nuclear NME1 gene and the protein subunits Rpp1p, Snm1p, Pop1p, Pop3p, Pop4p, Pop5p, Pop6p, Pop7p, Pop8p, and Rmp1p. RNase MRP processes pre-rRNAs in the nucleolus and is also present during mitosis in cytoplasmic RNA processing bodies, where it has a role in degradation of daughter cell-specific mRNAs via cleavage of 5' untranslated regions. In mammals, a portion of RNase MRP enters mitochondria and processes RNAs to create RNA primers for DNA replication, but this has not been shown in fungi.

Last updated: 2007-03-01 Contact SGD

References cited on this page View Complete Literature Guide for RPM1
1) Wise CA and Martin NC  (1991) Dramatic size variation of yeast mitochondrial RNAs suggests that RNase P RNAs can be quite small. J Biol Chem 266(29):19154-7
2) Hollingsworth MJ and Martin NC  (1986) RNase P activity in the mitochondria of Saccharomyces cerevisiae depends on both mitochondrion and nucleus-encoded components. Mol Cell Biol 6(4):1058-64
3) Martin NC and Lang BF  (1997) Mitochondrial RNase P: the RNA family grows. Nucleic Acids Symp Ser (36):42-4
4) Miller DL and Martin NC  (1983) Characterization of the yeast mitochondrial locus necessary for tRNA biosynthesis: DNA sequence analysis and identification of a new transcript. Cell 34(3):911-7
5) Miller DL, et al.  (1985) Polymorphism in the structure of the yeast mitochondrial tRNA synthesis locus. Nucleic Acids Res 13(3):859-72
6) Martin NC and Underbrink-Lyon K  (1981) A mitochondrial locus is necessary for the synthesis of mitochondrial tRNA in the yeast Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 78(8):4743-7
7) Underbrink-Lyon K, et al.  (1983) Characterization of a yeast mitochondrial locus necessary for tRNA biosynthesis. Deletion mapping and restriction mapping studies. Mol Gen Genet 191(3):512-8
8) Hollingsworth MJ and Martin NC  (1987) Alteration of a mitochondrial tRNA precursor 5' leader abolishes its cleavage by yeast mitochondrial RNase P. Nucleic Acids Res 15(21):8845-60
9) Dang YL and Martin NC  (1993) Yeast mitochondrial RNase P. Sequence of the RPM2 gene and demonstration that its product is a protein subunit of the enzyme. J Biol Chem 268(26):19791-6
10) Stribinskis V, et al.  (2001) Rpm2p: separate domains promote tRNA and Rpm1r maturation in Saccharomyces cerevisiae mitochondria. Nucleic Acids Res 29(17):3631-7
11) Morales MJ, et al.  (1989) Characterization of yeast mitochondrial RNase P: an intact RNA subunit is not essential for activity in vitro. Nucleic Acids Res 17(17):6865-81
12) Xiao S, et al.  (2001) Eukaryotic ribonuclease P: increased complexity to cope with the nuclear pre-tRNA pathway. J Cell Physiol 187(1):11-20