Summary: Mitochondrial ribosomal protein (VAR1)
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Mitochondrial ribosomal protein (VAR1) Provide feedback
This family consists of the yeast mitochondrial ribosomal proteins VAR1. Mitochondria possess their own ribosomes responsible for the synthesis of a small number of proteins encoded by the mitochondrial genome. In yeast the two ribosomal RNAs and a single ribosomal protein, VAR1, are products of mitochondrial genes, and the remaining approximately 80 ribosomal proteins are encoded in the nucleus . VAR1 along with 15S rRNA are necessary for the formation of mature 37S subunits .
Mason TL, Pan C, Sanchirico ME, Sirum-Connolly K; , Experientia 1996;52:1148-1157.: Molecular genetics of the peptidyl transferase center and the unusual Var1 protein in yeast mitochondrial ribosomes. PUBMED:8988258 EPMC:8988258
Davis SC, Ellis SR; , Mol Gen Genet 1995;247:379-386.: Incorporation of the yeast mitochondrial ribosomal protein Mrp2 into ribosomal subunits requires the mitochondrially encoded Var1 protein. PUBMED:7770043 EPMC:7770043
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR007980
Ribosomes are the particles that catalyse mRNA-directed protein synthesis in all organisms. The codons of the mRNA are exposed on the ribosome to allow tRNA binding. This leads to the incorporation of amino acids into the growing polypeptide chain in accordance with the genetic information. Incoming amino acid monomers enter the ribosomal A site in the form of aminoacyl-tRNAs complexed with elongation factor Tu (EF-Tu) and GTP. The growing polypeptide chain, situated in the P site as peptidyl-tRNA, is then transferred to aminoacyl-tRNA and the new peptidyl-tRNA, extended by one residue, is translocated to the P site with the aid the elongation factor G (EF-G) and GTP as the deacylated tRNA is released from the ribosome through one or more exit sites [PUBMED:11297922, PUBMED:11290319]. About 2/3 of the mass of the ribosome consists of RNA and 1/3 of protein. The proteins are named in accordance with the subunit of the ribosome which they belong to - the small (S1 to S31) and the large (L1 to L44). Usually they decorate the rRNA cores of the subunits.
Many ribosomal proteins, particularly those of the large subunit, are composed of a globular, surfaced-exposed domain with long finger-like projections that extend into the rRNA core to stabilise its structure. Most of the proteins interact with multiple RNA elements, often from different domains. In the large subunit, about 1/3 of the 23S rRNA nucleotides are at least in van der Waal's contact with protein, and L22 interacts with all six domains of the 23S rRNA. Proteins S4 and S7, which initiate assembly of the 16S rRNA, are located at junctions of five and four RNA helices, respectively. In this way proteins serve to organise and stabilise the rRNA tertiary structure. While the crucial activities of decoding and peptide transfer are RNA based, proteins play an active role in functions that may have evolved to streamline the process of protein synthesis. In addition to their function in the ribosome, many ribosomal proteins have some function 'outside' the ribosome [PUBMED:11290319, PUBMED:11114498].
This family consists of the VAR1 mitochondrial ribosomal proteins found in yeast. Mitochondria possess their own ribosomes responsible for the synthesis of a small number of proteins encoded by the mitochondrial genome. VAR1 is the only protein in the yeast mitochondrial ribosome to be encoded in the mitochondria - the remaining approximately 80 ribosomal proteins are encoded in the nucleus [PUBMED:8988258]. VAR1 along with 15S rRNA are necessary for the formation of mature 37S subunits [PUBMED:7770043].
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||mitochondrial ribosome (GO:0005761)|
|Molecular function||structural constituent of ribosome (GO:0003735)|
|Biological process||translation (GO:0006412)|
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|Seed source:||Pfam-B_7802 (release 7.7)|
|Number in seed:||5|
|Number in full:||28|
|Average length of the domain:||290.00 aa|
|Average identity of full alignment:||34 %|
|Average coverage of the sequence by the domain:||79.83 %|
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build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||7|
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