Description

IPR022801 is a Small ribosomal subunit protein uS4.

<p>This family includes the small ribosomal subunit protein uS4, also known as S9. U3 small nucleolar ribonucleoprotein protein IMP3, a component of the 60-80S U3 small nucleolar ribonucleoprotein (U3 snoRNP), is also included in this entry. It is required for the early cleavages during pre-18S ribosomal RNA processing [[cite:PUB00095723], [cite:PUB00151110]].</p> <p>Ribosomal protein uS4 is one of the proteins from the small ribosomal subunit. In Escherichia coli, uS4 is known to bind directly to 16S ribosomal RNA. Mutations in uS4 have been shown to increase translational error frequencies [[cite:PUB00004390]]. uS4 is a protein of 171 to 205 amino-acid residues (except for NAM9, which is much larger). The crystal structure of a bacterial uS4 protein revealed a two domain molecule. The first domain is composed of four helices in the known structure. The second domain is in the middle of the first one and displays some structural homology with the ETS DNA binding domain [[cite:PUB00001317]].</p> <p>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 [[cite:PUB00007068], [cite:PUB00007069]]. 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.</p> <p>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 [[cite:PUB00007069], [cite:PUB00007070]].</p>

This description is obtained from EB-eye REST.

Associated GO terms

Unable to find any GO terms for the transcript with the identifier.

Associated Lotus transcripts 21

Co-occuring domains 1

A list of co-occurring predicted domains within the L. japonicus gene space: