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| <SX load='3j5s' size='340' side='right' viewer='molstar' caption='[[3j5s]], [[Resolution|resolution]] 7.50Å' scene=''> | | <SX load='3j5s' size='340' side='right' viewer='molstar' caption='[[3j5s]], [[Resolution|resolution]] 7.50Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[3j5s]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [https://en.wikipedia.org/wiki/Escherichia_coli_mg1655 Escherichia coli mg1655]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3J5S OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3J5S FirstGlance]. <br> | | <table><tr><td colspan='2'>[[3j5s]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [https://en.wikipedia.org/wiki/Escherichia_coli_str._K-12_substr._MG1655 Escherichia coli str. K-12 substr. MG1655]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3J5S OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3J5S FirstGlance]. <br> |
| </td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">yjjK ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=511145 Escherichia coli MG1655])</td></tr> | | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 7.5Å</td></tr> |
| <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3j5s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3j5s OCA], [https://pdbe.org/3j5s PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3j5s RCSB], [https://www.ebi.ac.uk/pdbsum/3j5s PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3j5s ProSAT]</span></td></tr> | | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3j5s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3j5s OCA], [https://pdbe.org/3j5s PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3j5s RCSB], [https://www.ebi.ac.uk/pdbsum/3j5s PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3j5s ProSAT]</span></td></tr> |
| </table> | | </table> |
| == Function == | | == Function == |
| [[https://www.uniprot.org/uniprot/RL5_ECOLI RL5_ECOLI]] 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. Its 5S rRNA binding is significantly enhanced in the presence of L18.[HAMAP-Rule:MF_01333_B] In the 70S ribosome in the initiation state (PubMed:12809609) was modeled to contact protein S13 of the 30S subunit (bridge B1b), connecting the 2 subunits; the protein-protein contacts between S13 and L5 in B1b change in the model with bound EF-G implicating this bridge in subunit movement (PubMed:12809609 and PubMed:18723842). In the two 3.5 A resolved ribosome structures (PubMed:16272117) the contacts between L5, S13 and S19 are different, confirming the dynamic nature of this interaction.[HAMAP-Rule:MF_01333_B] Contacts the P site tRNA; the 5S rRNA and some of its associated proteins might help stabilize positioning of ribosome-bound tRNAs.[HAMAP-Rule:MF_01333_B] [[https://www.uniprot.org/uniprot/RS7_ECOLI RS7_ECOLI]] 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, where it has been shown to contact mRNA. Has been shown to contact tRNA in both the P and E sites; it probably blocks exit of the E site tRNA.<ref>PMID:2461734</ref> Protein S7 is also a translational repressor protein; it regulates the expression of the str operon members to different degrees by binding to its mRNA.<ref>PMID:2461734</ref> [[https://www.uniprot.org/uniprot/RL1_ECOLI RL1_ECOLI]] One of the primary rRNA binding proteins, it binds very close to the 3'-end of the 23S rRNA. Forms part of the L1 stalk. It is often not seen in high-resolution crystal structures, but can be seen in cryo_EM and 3D reconstruction models. These indicate that the distal end of the stalk moves by approximately 20 angstroms (PubMed:12859903). This stalk movement is thought to be coupled to movement of deacylated tRNA into and out of the E site, and thus to participate in tRNA translocation (PubMed:12859903). Contacts the P and E site tRNAs.[HAMAP-Rule:MF_01318_B] Protein L1 is also a translational repressor protein, it controls the translation of the L11 operon by binding to its mRNA.[HAMAP-Rule:MF_01318_B]
| | [https://www.uniprot.org/uniprot/ETTA_ECOLI ETTA_ECOLI] A translation factor that gates the progression of the 70S ribosomal initiation complex (IC, containing tRNA(fMet) in the P-site) into the translation elongation cycle by using a mechanism sensitive to the ATP/ADP ratio. Binds to the 70S ribosome E-site where it modulates the state of the translating ribosome during subunit translocation. Stimulates dipeptide bond synthesis in the presence of ATP (cell in high energy state), but inhibits dipeptide synthesis in the presence of ADP (cell in low energy state), and thus may control translation in response to changing ATP levels (including during stationary phase). Following ATP hydrolysis is probably released allowing the ribosome to enter the elongation phase. ATPase activity is stimulated in the presence of ribosomes. Its specificity for the IC may be conferred by its recognition of features unique to tRNA(fMet).<ref>PMID:24389465</ref> <ref>PMID:24389466</ref> |
| <div style="background-color:#fffaf0;">
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| == Publication Abstract from PubMed ==
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| Cells express many ribosome-interacting factors whose functions and molecular mechanisms remain unknown. Here, we elucidate the mechanism of a newly characterized regulatory translation factor, energy-dependent translational throttle A (EttA), which is an Escherichia coli representative of the ATP-binding cassette F (ABC-F) protein family. Using cryo-EM, we demonstrate that the ATP-bound form of EttA binds to the ribosomal tRNA-exit site, where it forms bridging interactions between the ribosomal L1 stalk and the tRNA bound in the peptidyl-tRNA-binding site. Using single-molecule fluorescence resonance energy transfer, we show that the ATP-bound form of EttA restricts ribosome and tRNA dynamics required for protein synthesis. This work represents the first example, to our knowledge, in which the detailed molecular mechanism of any ABC-F family protein has been determined and establishes a framework for elucidating the mechanisms of other regulatory translation factors.
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| EttA regulates translation by binding the ribosomal E site and restricting ribosome-tRNA dynamics.,Chen B, Boel G, Hashem Y, Ning W, Fei J, Wang C, Gonzalez RL Jr, Hunt JF, Frank J Nat Struct Mol Biol. 2014 Jan 5. doi: 10.1038/nsmb.2741. PMID:24389465<ref>PMID:24389465</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div> | |
| <div class="pdbe-citations 3j5s" style="background-color:#fffaf0;"></div>
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| ==See Also== | | ==See Also== |
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| </SX> | | </SX> |
| [[Category: Escherichia coli]] | | [[Category: Escherichia coli]] |
| [[Category: Escherichia coli mg1655]] | | [[Category: Escherichia coli str. K-12 substr. MG1655]] |
| [[Category: Large Structures]] | | [[Category: Large Structures]] |
| [[Category: Hashem, Y]] | | [[Category: Hashem Y]] |
| [[Category: Abc-f protein family]]
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| [[Category: Protein translation regulation]]
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| [[Category: Ribosome-translation complex]]
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| [[Category: Single-molecule fret]]
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| [[Category: Yjjk]]
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