5e81 | pdb_00005e81
Structure of T. thermophilus 70S ribosome complex with mRNA and tRNALys in the A-site with wobble pair
Structural highlights
Function[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). [RL5_THET8] 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 (forming bridge B1b) connecting the head of the 30S subunit to the top of the 50S subunit. The bridge itself contacts the P site tRNA and is implicated in movement during ribosome translocation. Also contacts the P site tRNA independently of the intersubunit bridge; the 5S rRNA and some of its associated proteins might help stabilize positioning of ribosome-bound tRNAs.[HAMAP-Rule:MF_01333_B] [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_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). [RS17_THET8] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it helps nucleate assembly of the platform and body of the 30S subunit by bringing together and stabilizing interactions between several different RNA helices. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit.[HAMAP-Rule:MF_01345] Deletion of the protein leads to an increased generation time and a temperature-sensitive phenotype.[HAMAP-Rule:MF_01345] [RS2_THET2] Spans the head-body hinge region of the 30S subunit. Is loosely associated with 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). [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). [RS16_THET2] Binds to the lower part of the body of the 30S subunit, where it stabilizes two of its domains (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). [RL1_THET2] Binds directly to 23S rRNA. The L1 stalk is quite mobile in the ribosome, and is involved in E site tRNA release (By similarity). Protein L1 is also a translational repressor protein, it controls the translation of the L11 operon by binding to its mRNA (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). [RS20_THET8] One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it nucleates assembly of the bottom of the body of the 30S subunit, by binding to several RNA helices of the 16S rRNA.[HAMAP-Rule:MF_00500] [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). [RS10_THET2] Involved in the binding of tRNA to the ribosomes (By similarity). [RL4_THET8] 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).[HAMAP-Rule:MF_01328_B] Forms part of the polypeptide exit tunnel (By similarity).[HAMAP-Rule:MF_01328_B] This protein can be incorporated into E.coli ribosomes in vivo, which resulted in decreased peptidyltransferase (Ptase) activity of the hybrid ribosomes. The hybrid 50S subunits associate less well with 30S subunits to form the ribosome.[HAMAP-Rule:MF_01328_B] [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). [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). [RL32_THET8] Found on the solvent side of the large subunit.[HAMAP-Rule:MF_00340] [RL27_THET8] Found on the solvent side of the large subunit.[HAMAP-Rule:MF_00539] [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). [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). [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). [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). [RS6_THET2] Located on the outer edge of the platform on the body of the 30S subunit (By similarity). [RL14_THET8] This protein binds directly to 23S ribosomal RNA (By similarity).[HAMAP-Rule:MF_01367] Contacts the 16S rRNA of the 30S subunit in two different positions helping to form bridges B5 and B8.[HAMAP-Rule:MF_01367] [RS3_THET2] Binds the lower part of the 30S subunit head. Binds mRNA in the 70S ribosome, positioning it for translation (By similarity). [RS9_THET8] 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.[HAMAP-Rule:MF_00532_B] [RL19_THET8] Contacts the 16S rRNA of the 30S subunit (part of bridge B6), connecting the 2 subunits.[HAMAP-Rule:MF_00402] [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). [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). [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). [RL31_THET2] Binds the 23S rRNA (By similarity). [RL16_THET8] This protein binds directly to 23S rRNA. Interacts with the A site tRNA.[HAMAP-Rule:MF_01342] [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). [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). [RL9_THET8] Binds to the 23S rRNA. Extends more that 50 Angstroms beyond the surface of the 70S ribosome.[HAMAP-Rule:MF_00503] [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). [RL15_THET2] Binds to the 23S rRNA (By similarity). [RL21_THET2] This protein binds to 23S rRNA in the presence of protein L20 (By similarity). [RS19_THET2] Protein S19 forms a complex with S13 that binds strongly to the 16S ribosomal RNA (By similarity). [RL34_THET8] Found on the solvent side of the large subunit.[HAMAP-Rule:MF_00391] [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). Publication Abstract from PubMedPosttranscriptional modifications at the wobble position of transfer RNAs play a substantial role in deciphering the degenerate genetic code on the ribosome. The number and variety of modifications suggest different mechanisms of action during messenger RNA decoding, of which only a few were described so far. Here, on the basis of several 70S ribosome complex X-ray structures, we demonstrate how Escherichia coli tRNA(Lys)UUU with hypermodified 5-methylaminomethyl-2-thiouridine (mnm(5)s(2)U) at the wobble position discriminates between cognate codons AAA and AAG, and near-cognate stop codon UAA or isoleucine codon AUA, with which it forms pyrimidine-pyrimidine mismatches. We show that mnm(5)s(2)U forms an unusual pair with guanosine at the wobble position that expands general knowledge on the degeneracy of the genetic code and specifies a powerful role of tRNA modifications in translation. Our models consolidate the translational fidelity mechanism proposed previously where the steric complementarity and shape acceptance dominate the decoding mechanism. Novel base-pairing interactions at the tRNA wobble position crucial for accurate reading of the genetic code.,Rozov A, Demeshkina N, Khusainov I, Westhof E, Yusupov M, Yusupova G Nat Commun. 2016 Jan 21;7:10457. doi: 10.1038/ncomms10457. PMID:26791911[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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