4v67 | pdb_00004v67
Crystal structure of a translation termination complex formed with release factor RF2.
Structural highlights
Function[RL11_THETH] This protein binds directly to 23S ribosomal RNA (By similarity). [RL9_THET2] Binds to the 23S rRNA (By similarity). [RS19_THET2] Protein S19 forms a complex with S13 that binds strongly to the 16S ribosomal RNA (By similarity). [RS5_THET2] With S4 and S12 plays an important role in translational accuracy (By similarity). Located at the back of the 30S subunit body where it stabilizes the conformation of the head with respect to the body (By similarity). [RS15_THET2] 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 (By similarity). Forms an intersubunit bridge (bridge B4) with the 23S rRNA of the 50S subunit in the ribosome (By similarity). [RS16_THET2] Binds to the lower part of the body of the 30S subunit, where it stabilizes two of its domains (By similarity). [RL5_THET2] This is 1 of the proteins that binds and probably mediates the attachment of the 5S RNA into the large ribosomal subunit, where it forms part of the central protuberance. In the 70S ribosome it contacts protein S13 of the 30S subunit (bridge B1b), connecting the 2 subunits; this bridge is implicated in subunit movement. Contacts the P site tRNA; the 5S rRNA and some of its associated proteins might help stabilize positioning of ribosome-bound tRNAs (By similarity). [RS14Z_THET2] 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). [RL23_THET2] One of the early assembly proteins it binds 23S rRNA. One of the proteins that surrounds the polypeptide exit tunnel on the outside of the ribosome. Forms the main docking site for trigger factor binding to the ribosome (By similarity). [RL2_THET2] One of the primary rRNA binding proteins. Required for association of the 30S and 50S subunits to form the 70S ribosome, for tRNA binding and peptide bond formation. It has been suggested to have peptidyltransferase activity; this is somewhat controversial. Makes several contacts with the 16S rRNA in the 70S ribosome (By similarity). [RL3_THET2] One of the primary rRNA binding proteins, it binds directly near the 3'-end of the 23S rRNA, where it nucleates assembly of the 50S subunit (By similarity). [RL19_THET2] This protein is located at the 30S-50S ribosomal subunit interface and may play a role in the structure and function of the aminoacyl-tRNA binding site (By similarity). [RS12_THET2] With S4 and S5 plays an important role in translational accuracy (By similarity). Interacts with and stabilizes bases of the 16S rRNA that are involved in tRNA selection in the A site and with the mRNA backbone. Located at the interface of the 30S and 50S subunits, it traverses the body of the 30S subunit contacting proteins on the other side and probably holding the rRNA structure together. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit (By similarity). [RS18_THET2] 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). [Q72GJ6_THET2] Peptide chain release factor 2 directs the termination of translation in response to the peptide chain termination codons UGA and UAA (By similarity). [RS8_THET2] 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). [RL6_THET2] This protein binds to the 23S rRNA, and is important in its secondary structure. It is located near the subunit interface in the base of the L7/L12 stalk, and near the tRNA binding site of the peptidyltransferase center (By similarity). [RL14_THET2] Binds to 23S rRNA. Forms part of two intersubunit bridges in the 70S ribosome (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). [RL21_THET2] This protein binds to 23S rRNA in the presence of protein L20 (By similarity). [RS20_THET2] Binds directly to 16S ribosomal RNA (By similarity). [RL25_THET2] This is one of the proteins that binds to the 5S RNA in the ribosome where it forms part of the central protuberance (By similarity). [RS11_THET2] 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 (By similarity). [RSHX_THET2] 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). [RL4_THET2] One of the primary rRNA binding proteins, this protein initially binds near the 5'-end of the 23S rRNA. 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). Forms part of the polypeptide exit tunnel (By similarity). [RS4_THET2] 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 (By similarity). [RL18_THET2] This is one of the proteins that binds and probably mediates the attachment of the 5S RNA into the large ribosomal subunit, where it forms part of the central protuberance (By similarity). [RL15_THET2] Binds to the 23S rRNA (By similarity). [RS7_THET2] One of the primary rRNA binding proteins, it binds directly to 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, probably blocks exit of the E-site tRNA (By similarity). [RL31_THET2] Binds the 23S rRNA (By similarity). [RL20_THET2] Binds directly to 23S ribosomal RNA and is necessary for the in vitro assembly process of the 50S ribosomal subunit. It is not involved in the protein synthesizing functions of that subunit (By similarity). [RS10_THET2] Involved in the binding of tRNA to the ribosomes (By similarity). [RS13_THET2] Located at the top of the head of the 30S subunit, it contacts several helices of the 16S rRNA. In the 70S ribosome it contacts the 23S rRNA (bridge B1a) and protein L5 of the 50S subunit (bridge B1b), connecting the 2 subunits; these bridges are implicated in subunit movement. Contacts the tRNAs in the A and P-sites (By similarity). [RS6_THET2] Located on the outer edge of the platform on the body of the 30S subunit (By similarity). [RL32_THET2] Found on the solvent side of the large subunit (By similarity). [RS2_THET2] Spans the head-body hinge region of the 30S subunit. Is loosely associated with the 30S subunit (By similarity). [RL13_THET2] This protein is one of the early assembly proteins of the 50S ribosomal subunit, although it is not seen to bind rRNA by itself. It is important during the early stages of 50S assembly (By similarity). [RL24_THET2] One of two assembly initiator proteins, it binds directly to the 5'-end of the 23S rRNA, where it nucleates assembly of the 50S subunit (By similarity). One of the proteins that surrounds the polypeptide exit tunnel on the outside of the subunit (By similarity). [RL16_THET2] Binds 23S rRNA and is also seen to make contacts with the A and possibly P site tRNAs (By similarity). [RL22_THET2] 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 located near the polypeptide exit tunnel on the outside of the subunit, while an extended beta-hairpin is found that lines the wall of the exit tunnel in the center of the 70S ribosome (By similarity). [RS17_THET2] One of the primary rRNA binding proteins, it binds specifically to the 5'-end of 16S ribosomal RNA (By similarity). [RL34_THET8] Found on the solvent side of the large subunit.[HAMAP-Rule:MF_00391] [RS3_THET2] Binds the lower part of the 30S subunit head. Binds mRNA in the 70S ribosome, positioning it for translation (By similarity). Publication Abstract from PubMedWe report the crystal structure of a translation termination complex formed by the Thermus thermophilus 70S ribosome bound with release factor RF2, in response to a UAA stop codon, solved at 3 A resolution. The backbone of helix alpha5 and the side chain of serine of the conserved SPF motif of RF2 recognize U1 and A2 of the stop codon, respectively. A3 is unstacked from the first 2 bases, contacting Thr-216 and Val-203 of RF2 and stacking on G530 of 16S rRNA. The structure of the RF2 complex supports our previous proposal that conformational changes in the ribosome in response to recognition of the stop codon stabilize rearrangement of the switch loop of the release factor, resulting in docking of the universally conserved GGQ motif in the PTC of the 50S subunit. As seen for the RF1 complex, the main-chain amide nitrogen of glutamine in the GGQ motif is positioned to contribute directly to catalysis of peptidyl-tRNA hydrolysis, consistent with mutational studies, which show that most side-chain substitutions of the conserved glutamine have little effect. We show that when the H-bonding capability of the main-chain N-H of the conserved glutamine is eliminated by substitution with proline, peptidyl-tRNA esterase activity is abolished, consistent with its proposed role in catalysis. Crystal structure of a translation termination complex formed with release factor RF2.,Korostelev A, Asahara H, Lancaster L, Laurberg M, Hirschi A, Zhu J, Trakhanov S, Scott WG, Noller HF Proc Natl Acad Sci U S A. 2008 Dec 16;105(50):19684-9. Epub 2008 Dec 8. PMID:19064930[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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