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5n8o
From Proteopedia
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| - | '''Unreleased structure''' | ||
| - | + | ==Cryo EM structure of the conjugative relaxase TraI of the F/R1 plasmid system== | |
| + | <SX load='5n8o' size='340' side='right' viewer='molstar' caption='[[5n8o]], [[Resolution|resolution]] 3.90Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[5n8o]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5N8O OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5N8O FirstGlance]. <br> | ||
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.9Å</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=5n8o FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5n8o OCA], [https://pdbe.org/5n8o PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5n8o RCSB], [https://www.ebi.ac.uk/pdbsum/5n8o PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5n8o ProSAT]</span></td></tr> | ||
| + | </table> | ||
| + | == Function == | ||
| + | [https://www.uniprot.org/uniprot/TRAI1_ECOLI TRAI1_ECOLI] Conjugative DNA transfer (CDT) is the unidirectional transfer of ssDNA plasmid from a donor to a recipient cell. It is the central mechanism by which antibiotic resistance and virulence factors are propagated in bacterial populations. Part of the relaxosome, which facilitates a site- and strand-specific cut in the origin of transfer by TraI, at the nic site. Relaxosome formation requires binding of IHF and TraY to the oriT region, which then faciliates binding of TraI relaxase. TraI forms a covalent 5'-phosphotyrosine intermediate linkage to the ssDNA. The transesterified T-strand moves from the donor cell to the recipient cell in a 5'to 3' direction, with the DNA helicase activity of TraI unwinding the DNA. DNA transfer occurs via the conjugative pore (transferosome) an intercellular junction mediated by a type IV secretion system, with TraD providing the means to link the relaxosome to the conjugative pore. The relaxase completes DNA transfer by reversing the covalent phosphotyrosine linkage and releasing the T-strand.<ref>PMID:12637015</ref> <ref>PMID:6308637</ref> <ref>PMID:8386720</ref> <ref>PMID:7499339</ref> <ref>PMID:11560509</ref> TraI has also been identified as DNA helicase I. DNA. helicase I is a potent, highly processive DNA-dependent ATPase, able to unwind about 1.1 kb dsDNA per second in a 5' to 3' manner.<ref>PMID:12637015</ref> <ref>PMID:6308637</ref> <ref>PMID:8386720</ref> <ref>PMID:7499339</ref> <ref>PMID:11560509</ref> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Relaxases play essential roles in conjugation, the main process by which bacteria exchange genetic material, notably antibiotic resistance genes. They are bifunctional enzymes containing a trans-esterase activity, which is responsible for nicking the DNA strand to be transferred and for covalent attachment to the resulting 5'-phosphate end, and a helicase activity, which is responsible for unwinding the DNA while it is being transported to a recipient cell. Here we show that these two activities are carried out by two conformers that can both load simultaneously on the origin of transfer DNA. We solve the structure of one of these conformers by cryo electron microscopy to near-atomic resolution, elucidating the molecular basis of helicase function by relaxases and revealing insights into the mechanistic events taking place in the cell prior to substrate transport during conjugation. | ||
| - | + | Cryo-EM Structure of a Relaxase Reveals the Molecular Basis of DNA Unwinding during Bacterial Conjugation.,Ilangovan A, Kay CWM, Roier S, El Mkami H, Salvadori E, Zechner EL, Zanetti G, Waksman G Cell. 2017 May 4;169(4):708-721.e12. doi: 10.1016/j.cell.2017.04.010. Epub 2017, Apr 27. PMID:28457609<ref>PMID:28457609</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | [[Category: | + | </div> |
| + | <div class="pdbe-citations 5n8o" style="background-color:#fffaf0;"></div> | ||
| + | |||
| + | ==See Also== | ||
| + | *[[Helicase 3D structures|Helicase 3D structures]] | ||
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </SX> | ||
| + | [[Category: Escherichia coli]] | ||
| + | [[Category: Large Structures]] | ||
| + | [[Category: Ilangovan A]] | ||
| + | [[Category: Waksman G]] | ||
| + | [[Category: Zanetti G]] | ||
Current revision
Cryo EM structure of the conjugative relaxase TraI of the F/R1 plasmid system
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