2uxc
CRYSTAL STRUCTURE OF AN EXTENDED TRNA ANTICODON STEM LOOP IN COMPLEX WITH ITS COGNATE MRNA UCGU IN THE CONTEXT OF THE THERMUS THERMOPHILUS 30S SUBUNIT.CRYSTAL STRUCTURE OF AN EXTENDED TRNA ANTICODON STEM LOOP IN COMPLEX WITH ITS COGNATE MRNA UCGU IN THE CONTEXT OF THE THERMUS THERMOPHILUS 30S SUBUNIT.
Structural highlights
Function[RSHX_THET8] 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. [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] [RS2_THET8] Spans the head-body hinge region of the 30S subunit. Is loosely associated with the 30S subunit.[HAMAP-Rule:MF_00291_B] [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] [RS18_THET8] Located on the back of the platform of the 30S subunit where it stabilizes the close packing of several RNA helices of the 16S rRNA. Forms part of the Shine-Dalgarno cleft in the 70S ribosome, where it probably interacts with the Shine-Dalgarno helix.[HAMAP-Rule:MF_00270] [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] [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] [RS10_THET8] Part of the top of the 30S subunit head.[HAMAP-Rule:MF_00508] [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] [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] [RS6_THET8] Located on the outer edge of the platform on the body of the 30S subunit.[HAMAP-Rule:MF_00360] [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] [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] [RS12_THET8] With S4 and S5 plays an important role in translational accuracy (By similarity).[HAMAP-Rule:MF_00403_B] 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.[HAMAP-Rule:MF_00403_B] [RS15_THET8] 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).[HAMAP-Rule:MF_01343] Forms an intersubunit bridge (bridge B4) with the 23S rRNA of the 50S subunit in the ribosome.[HAMAP-Rule:MF_01343] [RS8_THET8] 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 central domain. The combined cluster of proteins S8, S12 and S17 appears to hold together the shoulder and platform of the 30S subunit.[HAMAP-Rule:MF_01302_B] [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] [RS19_THET8] Located at the top of the head of the 30S subunit, extending towards the 50S subunit, which it may contact in the 70S complex. Contacts several RNA helices of the 16S rRNA.[HAMAP-Rule:MF_00531] [RS5_THET8] 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. Binds mRNA in the 70S ribosome, positioning it for translation.[HAMAP-Rule:MF_01307_B] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDuring translation, some +1 frameshift mRNA sites are decoded by frameshift suppressor tRNAs that contain an extra base in their anticodon loops. Similarly engineered tRNAs have been used to insert nonnatural amino acids into proteins. Here, we report crystal structures of two anticodon stem-loops (ASLs) from tRNAs known to facilitate +1 frameshifting bound to the 30S ribosomal subunit with their cognate mRNAs. ASL(CCCG) and ASL(ACCC) (5'-3' nomenclature) form unpredicted anticodon-codon interactions where the anticodon base 34 at the wobble position contacts either the fourth codon base or the third and fourth codon bases. In addition, we report the structure of ASL(ACGA) bound to the 30S ribosomal subunit with its cognate mRNA. The tRNA containing this ASL was previously shown to be unable to facilitate +1 frameshifting in competition with normal tRNAs (Hohsaka et al. 2001), and interestingly, it displays a normal anticodon-codon interaction. These structures show that the expanded anticodon loop of +1 frameshift promoting tRNAs are flexible enough to adopt conformations that allow three bases of the anticodon to span four bases of the mRNA. Therefore it appears that normal triplet pairing is not an absolute constraint of the decoding center. Structures of tRNAs with an expanded anticodon loop in the decoding center of the 30S ribosomal subunit.,Dunham CM, Selmer M, Phelps SS, Kelley AC, Suzuki T, Joseph S, Ramakrishnan V RNA. 2007 Jun;13(6):817-23. Epub 2007 Apr 6. PMID:17416634[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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