1qvf
From Proteopedia
Structure of a deacylated tRNA minihelix bound to the E site of the large ribosomal subunit of Haloarcula marismortui
Structural highlights
Function[RL23_HALMA] Binds to a specific region on the 23S rRNA. Located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_01369] [RL5_HALMA] This is 1 of 5 proteins that mediates the attachment of the 5S rRNA onto the large ribosomal subunit, stabilizing the orientation of adjacent RNA domains. Forms part of the central protuberance. Modeling places the A and P site tRNAs in close proximity to this protein; the 5S rRNA and some of its associated proteins might help stabilize positioning of ribosome-bound tRNAs. In the 70S ribosome it is thought to contact protein S13 of the 30S subunit (bridge B1b), connecting the 2 subunits; this bridge is implicated in subunit movement.[HAMAP-Rule:MF_01333_A] [RL31_HALMA] Binds to the 23S rRNA. Located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_00410] [RL18E_HALMA] Stabilizes the tertiary rRNA structure within the 23S rRNA domain (domain II) to which it binds.[HAMAP-Rule:MF_00329] [RL24_HALMA] 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).[HAMAP-Rule:MF_01326_A] Stabilizes the tertiary rRNA structure within the 23S rRNA domain (domain I) to which it binds. Located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_01326_A] [RL19E_HALMA] Binds to the 23S rRNA. Located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_01475] [RL39_HALMA] Binds to the 23S rRNA. Forms part of the polypeptide exit tunnel.[HAMAP-Rule:MF_00629] [RL24E_HALMA] Binds to the 23S rRNA.[HAMAP-Rule:MF_00773] [RL14_HALMA] Forms part of two intersubunit bridges in the 70S ribosome (By similarity). Binds to 23S rRNA.[HAMAP-Rule:MF_01367] [RL18_HALMA] This is one of 5 proteins that mediate the attachment of the 5S rRNA onto the large ribosomal subunit, where it forms part of the central protuberance and stabilizes the orientation of adjacent RNA domains.[HAMAP-Rule:MF_01337_A] [RL37_HALMA] Binds to the 23S rRNA.[HAMAP-Rule:MF_00547] [RL4_HALMA] 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 (By similarity).[HAMAP-Rule:MF_01328_A] Makes multiple contacts with different domains of the 23S rRNA in the assembled 50S subunit.[HAMAP-Rule:MF_01328_A] Forms part of the polypeptide exit tunnel, in which it helps forms a bend with protein L22. Contacts the macrolide antibiotic spiramycin in the polypeptide exit tunnel.[HAMAP-Rule:MF_01328_A] [RL32_HALMA] Binds to the 23S rRNA.[HAMAP-Rule:MF_00810] [RL30_HALMA] This is one of 5 proteins that mediate the attachment of the 5S rRNA onto the large ribosomal subunit, stabilizing the orientation of adjacent RNA domains.[HAMAP-Rule:MF_01371] [RL7A_HALMA] Multifunctional RNA-binding protein that recognizes the K-turn motif in ribosomal RNA, box H/ACA and box C/D sRNAs (By similarity).[HAMAP-Rule:MF_00326] [RL13_HALMA] This protein is one of the early assembly proteins of the 50S ribosomal subunit (By similarity). Binds to 23S rRNA.[HAMAP-Rule:MF_01366] [RL15_HALMA] Binds to the 23S rRNA.[HAMAP-Rule:MF_01341_A] [RL22_HALMA] This protein binds specifically to 23S rRNA. It makes multiple contacts with different domains of the 23S rRNA in the assembled 50S subunit and ribosome (By similarity).[HAMAP-Rule:MF_01331] Contacts all 6 domains of the 23S rRNA, helping stabilize their relative orientation. An extended beta-hairpin in the C-terminus forms part of the polypeptide exit tunnel, in which it helps forms a bend with protein L4, while most of the rest of the protein is located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_01331] [RL6_HALMA] 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.[HAMAP-Rule:MF_01365] [RL2_HALMA] 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).[HAMAP-Rule:MF_01320_A] [RL29_HALMA] Stabilizes the tertiary rRNA structure within the 23S rRNA domain (domain I) to which it binds. Located at the polypeptide exit tunnel on the outside of the subunit.[HAMAP-Rule:MF_00374] [RLA0_HALMA] Ribosomal protein L10e is the functional equivalent of E.coli protein L10.[HAMAP-Rule:MF_00280] [RL21_HALMA] This is one of 5 proteins that mediate the attachment of the 5S rRNA onto the large ribosomal subunit, stabilizing the orientation of adjacent RNA domains.[HAMAP-Rule:MF_00369] [RL44E_HALMA] Binds to the 23S rRNA. Binds deacetylated tRNA in the E site; when the tRNA binds a stretch of 7 amino acids are displaced to allow binding.[HAMAP-Rule:MF_01476] [RL3_HALMA] 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).[HAMAP-Rule:MF_01325_A] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDuring translation, tRNAs cycle through three binding sites on the ribosome: the A, the P, and the E sites. We have determined the structures of complexes between the Haloarcula marismortui large ribosomal subunit and two different E site substrates: a deacylated tRNA acceptor stem minihelix and a CCA-acceptor end. Both of these tRNA mimics contain analogs of adenosine 76, the component responsible for a large proportion of E site binding affinity. They bind in the center of the loop-extension of protein L44e, and make specific contacts with both L44e and 23S rRNA including bases that are conserved in all three kingdoms of life. These contacts are consistent with the footprinting, protection, and cross-linking data that have identified the E site biochemically. These structures explain the specificity of the E site for deacylated tRNAs, as it is too small to accommodate any relevant aminoacyl-tRNA. The orientation of the minihelix suggests that it may mimic the P/E hybrid state. It appears that the E site on the 50S subunit was formed by only RNA in the last common ancestor of the three kingdoms, since the proteins at the E sites of H. marismortui and Deinucoccus radiodurans large subunits are not homologous. Structures of deacylated tRNA mimics bound to the E site of the large ribosomal subunit.,Schmeing TM, Moore PB, Steitz TA RNA. 2003 Nov;9(11):1345-52. PMID:14561884[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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