| UniProt functional annotation for P0CH08 | |||
| UniProt code: P0CH08. |
| Organism: | Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast). | |
| Taxonomy: | Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes; Saccharomycetales; Saccharomycetaceae; Saccharomyces. | |
| Function: | [Ubiquitin]: Exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell- cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, and DNA-damage responses. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored- polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling (By similarity). {ECO:0000250}. | |
| Function: | [60S ribosomal protein L40-A]: Component of the ribosome, a large ribonucleoprotein complex responsible for the synthesis of proteins in the cell. The small ribosomal subunit (SSU) binds messenger RNAs (mRNAs) and translates the encoded message by selecting cognate aminoacyl-transfer RNA (tRNA) molecules. The large subunit (LSU) contains the ribosomal catalytic site termed the peptidyl transferase center (PTC), which catalyzes the formation of peptide bonds, thereby polymerizing the amino acids delivered by tRNAs into a polypeptide chain. The nascent polypeptides leave the ribosome through a tunnel in the LSU and interact with protein factors that function in enzymatic processing, targeting, and the membrane insertion of nascent chains at the exit of the ribosomal tunnel (PubMed:22096102). eL40 is essential for translation of a subset of cellular transcripts, including stress response transcripts, such as DDR2 (PubMed:23169626). {ECO:0000269|PubMed:23169626, ECO:0000305|PubMed:22096102}. | |
| Subunit: | Component of the large ribosomal subunit (LSU). Mature yeast ribosomes consist of a small (40S) and a large (60S) subunit. The 40S small subunit contains 1 molecule of ribosomal RNA (18S rRNA) and 33 different proteins (encoded by 57 genes). The large 60S subunit contains 3 rRNA molecules (25S, 5.8S and 5S rRNA) and 46 different proteins (encoded by 81 genes) (PubMed:9559554, PubMed:22096102). {ECO:0000269|PubMed:22096102, ECO:0000305|PubMed:9559554}. | |
| Subcellular location: | [Ubiquitin]: Cytoplasm {ECO:0000250}. Nucleus {ECO:0000250}. | |
| Subcellular location: | [60S ribosomal protein L40-A]: Cytoplasm {ECO:0000269|PubMed:22096102}. | |
| Miscellaneous: | Ubiquitin is encoded by several different genes. UBI1 and UBI2 genes code for a single copy of ubiquitin fused to the ribosomal proteins eL40. UBI3 is a polyprotein with one copy of ubiquitin fused to ribosomal protein eS31. UBI4 is a polyprotein containing 5 exact head to tail repeats of ubiquitin. {ECO:0000305|PubMed:3038523}. | |
| Miscellaneous: | The 60S ribosomal protein L40 is present with 40000 molecules/cell in log phase SD medium. {ECO:0000269|PubMed:14562106}. | |
| Similarity: | In the N-terminal section; belongs to the ubiquitin family. {ECO:0000305}. | |
| Similarity: | In the C-terminal section; belongs to the eukaryotic ribosomal protein eL40 family. {ECO:0000305}. | |
Annotations taken from UniProtKB at the EBI.