4v4r | pdb_00004v4r
Crystal structure of the whole ribosomal complex.
Structural highlights
Function[RS18_THETH] Binds as a heterodimer with protein S6 to the central domain of the 16S rRNA, where it helps stabilize the platform of the 30S subunit (By similarity). [RS4_THET8] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it helps nucleate assembly of the body and platform of the 30S subunit. Binds mRNA in the 70S ribosome, positioning it for translation.[HAMAP-Rule:MF_01306_B] [RS14Z_THETH] Binds 16S rRNA, required for the assembly of 30S particles and may also be responsible for determining the conformation of the 16S rRNA at the A site (By similarity). [RS15_THETH] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it helps nucleate assembly of the platform of the 30S subunit by binding and bridging several RNA helices of the 16S rRNA. Forms an intersubunit bridge (bridge B4) with the 23S rRNA of the 50S subunit in the ribosome (By similarity). [RS13_THET8] Located at the top of the head of the 30S subunit, it contacts several helices of the 16S rRNA. In the 70S ribosome structure it contacts the 23S rRNA (bridge B1a) and protein L5 of the 50S subunit (bridge B1b), connecting the top of the two subunits; these bridges are in contact with the A site and P site tRNAs respectively and are implicated in movement during ribosome translocation. Separately contacts the tRNAs in the A and P sites.[HAMAP-Rule:MF_01315] [RF1_THET8] Peptide chain release factor 1 directs the termination of translation in response to the peptide chain termination codons UAG and UAA (By similarity). [RL22_THETH] This protein binds specifically to 23S rRNA; its binding is stimulated by other ribosomal proteins, e.g. L4, L17, and L20. It is important during the early stages of 50S assembly. It makes multiple contacts with different domains of the 23S rRNA in the assembled 50S subunit and ribosome (By similarity). The globular domain of the protein is one of the proteins that surrounds the polypeptide exit tunnel on the outside of the subunit, while an extended beta-hairpin is found that penetrates into the center of the 70S ribosome. This extension seems to form part of the wall of the exit tunnel (By similarity). Deleting residues 82 to 84 (the equivalent deletion in E.coli renders cells resistant to erythromycin) would probably cause the tip of the hairpin to penetrate into the tunnel. [RS11_THET8] Located on the upper part of the platform of the 30S subunit, where it bridges several disparate RNA helices of the 16S rRNA. Forms part of the Shine-Dalgarno cleft in the 70S ribosome, where it interacts both with the Shine-Dalgarno helix and mRNA.[HAMAP-Rule:MF_01310] [RS17_THETH] One of the primary rRNA binding proteins, it binds specifically to the 5'-end of 16S ribosomal RNA (By similarity). [RSHX_THETH] Binds at the top of the head of the 30S subunit. It stabilizes a number of different RNA elements and thus is important for subunit structure (By similarity). [RS7_THET8] One of the primary rRNA binding proteins, it binds directly to 3'-end of the 16S rRNA where it nucleates assembly of the head domain of the 30S subunit. Is located at the subunit interface close to the decoding center. Binds mRNA and the E site tRNA blocking its exit path in the ribosome. This blockage implies that this section of the ribosome must be able to move to release the deacetylated tRNA.[HAMAP-Rule:MF_00480_B] [RS8_THETH] One of the primary rRNA binding proteins, it binds directly to 16S rRNA central domain where it helps coordinate assembly of the platform of the 30S subunit (By similarity). [RS19_THETH] Protein S19 forms a complex with S13 that binds strongly to the 16S ribosomal RNA (By similarity). [RS10_THETH] Involved in the binding of tRNA to the ribosomes (By similarity). [RS20_THET2] Binds directly to 16S ribosomal RNA (By similarity). [RS3_THET8] Binds the lower part of the 30S subunit head. Binds mRNA in the 70S ribosome, positioning it for translation.[HAMAP-Rule:MF_01309_B] [RS6_THETH] Located on the outer edge of the platform on the body of the 30S subunit (By similarity). [RS9_THET2] Part of the top of the head of the 30S subunit. The C-terminal region penetrates the head emerging in the P-site where it contacts tRNA (By similarity). [RS5_THETH] With S4 and S12 plays an important role in translational accuracy (By similarity).[HAMAP-Rule:MF_01307_B] Located at the back of the 30S subunit body where it stabilizes the conformation of the head with respect to the body (By similarity).[HAMAP-Rule:MF_01307_B] [RS16_THET8] Binds to the lower part of the body of the 30S subunit, where it stabilizes two of its domains.[HAMAP-Rule:MF_00385] [RS2_THET8] Spans the head-body hinge region of the 30S subunit. Is loosely associated with the 30S subunit.[HAMAP-Rule:MF_00291_B] Publication Abstract from PubMedDuring protein synthesis, translational release factors catalyze the release of the polypeptide chain when a stop codon on the mRNA reaches the A site of the ribosome. The detailed mechanism of this process is currently unknown. We present here the crystal structures of the ribosome from Thermus thermophilus with RF1 and RF2 bound to their cognate stop codons, at resolutions of 5.9 Angstrom and 6.7 Angstrom, respectively. The structures reveal details of interactions of the factors with the ribosome and mRNA, including elements previously implicated in decoding and peptide release. They also shed light on conformational changes both in the factors and in the ribosome during termination. Differences seen in the interaction of RF1 and RF2 with the L11 region of the ribosome allow us to rationalize previous biochemical data. Finally, this work demonstrates the feasibility of crystallizing ribosomes with bound factors at a defined state along the translational pathway. Crystal structures of the ribosome in complex with release factors RF1 and RF2 bound to a cognate stop codon.,Petry S, Brodersen DE, Murphy FV 4th, Dunham CM, Selmer M, Tarry MJ, Kelley AC, Ramakrishnan V Cell. 2005 Dec 29;123(7):1255-66. PMID:16377566[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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