8b1r
From Proteopedia
(Difference between revisions)
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[8b1r]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [https://en.wikipedia.org/wiki/Escherichia_phage_T7 Escherichia phage T7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8B1R OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8B1R FirstGlance]. <br> | <table><tr><td colspan='2'>[[8b1r]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] and [https://en.wikipedia.org/wiki/Escherichia_phage_T7 Escherichia phage T7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8B1R OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8B1R FirstGlance]. <br> | ||
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></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]] 3.2Å</td></tr> |
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></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=8b1r FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8b1r OCA], [https://pdbe.org/8b1r PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8b1r RCSB], [https://www.ebi.ac.uk/pdbsum/8b1r PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8b1r 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=8b1r FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8b1r OCA], [https://pdbe.org/8b1r PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8b1r RCSB], [https://www.ebi.ac.uk/pdbsum/8b1r PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8b1r ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
| - | [https://www.uniprot.org/uniprot/ | + | [https://www.uniprot.org/uniprot/RECC_ECOLI RECC_ECOLI] A helicase/nuclease that prepares dsDNA breaks (DSB) for recombinational DNA repair. Binds to DSBs and unwinds DNA via a rapid (>1 kb/second) and highly processive (>30 kb) ATP-dependent bidirectional helicase. Unwinds dsDNA until it encounters a Chi (crossover hotspot instigator, 5'-GCTGGTGG-3') sequence from the 3' direction. Cuts ssDNA a few nucleotides 3' to Chi site, by nicking one strand or switching the strand degraded (depending on the reaction conditions). The properties and activities of the enzyme are changed at Chi. The Chi-altered holoenzyme produces a long 3'-ssDNA overhang which facilitates RecA-binding to the ssDNA for homologous DNA recombination and repair. Holoenzyme degrades any linearized DNA that is unable to undergo homologous recombination (PubMed:4562392, PubMed:4552016, PubMed:123277). In the holoenzyme this subunit almost certainly recognizes the wild-type Chi sequence, when added to isolated RecB increases its ATP-dependent helicase processivity. The RecBC complex requires the RecD subunit for nuclease activity, but can translocate along ssDNA in both directions.<ref>PMID:10197988</ref> <ref>PMID:10884344</ref> <ref>PMID:123277</ref> <ref>PMID:12815437</ref> <ref>PMID:12815438</ref> <ref>PMID:1535156</ref> <ref>PMID:16041061</ref> <ref>PMID:1618858</ref> <ref>PMID:20852646</ref> <ref>PMID:23851395</ref> <ref>PMID:4268693</ref> <ref>PMID:4552016</ref> <ref>PMID:4562392</ref> <ref>PMID:7608206</ref> <ref>PMID:9192629</ref> <ref>PMID:9230304</ref> <ref>PMID:9448271</ref> <ref>PMID:9790841</ref> |
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
| - | Following infection of bacterial cells, bacteriophage modulate double-stranded DNA break repair pathways to protect themselves from host immunity systems and prioritise their own recombinases. Here we present biochemical and structural analysis of two phage proteins, gp5.9 and Abc2, which target the DNA break resection complex RecBCD. These exemplify two contrasting mechanisms for control of DNA break repair in which the RecBCD complex is either inhibited or co-opted for the benefit of the invading phage. Gp5.9 completely inhibits RecBCD by preventing it from binding to DNA. The RecBCD-gp5.9 structure shows that gp5.9 acts by substrate mimicry, binding predominantly to the RecB arm domain and competing sterically for the DNA binding site. Gp5.9 adopts a parallel coiled-coil architecture that is unprecedented for a natural DNA mimic protein. In contrast, binding of Abc2 does not substantially affect the biochemical activities of isolated RecBCD. The RecBCD-Abc2 structure shows that Abc2 binds to the Chi-recognition domains of the RecC subunit in a position that might enable it to mediate the loading of phage recombinases onto its single-stranded DNA products. | + | Following infection of bacterial cells, bacteriophage modulate double-stranded DNA break repair pathways to protect themselves from host immunity systems and prioritise their own recombinases. Here, we present biochemical and structural analysis of two phage proteins, gp5.9 and Abc2, which target the DNA break resection complex RecBCD. These exemplify two contrasting mechanisms for control of DNA break repair in which the RecBCD complex is either inhibited or co-opted for the benefit of the invading phage. Gp5.9 completely inhibits RecBCD by preventing it from binding to DNA. The RecBCD-gp5.9 structure shows that gp5.9 acts by substrate mimicry, binding predominantly to the RecB arm domain and competing sterically for the DNA binding site. Gp5.9 adopts a parallel coiled-coil architecture that is unprecedented for a natural DNA mimic protein. In contrast, binding of Abc2 does not substantially affect the biochemical activities of isolated RecBCD. The RecBCD-Abc2 structure shows that Abc2 binds to the Chi-recognition domains of the RecC subunit in a position that might enable it to mediate the loading of phage recombinases onto its single-stranded DNA products. |
Structures of RecBCD in complex with phage-encoded inhibitor proteins reveal distinctive strategies for evasion of a bacterial immunity hub.,Wilkinson M, Wilkinson OJ, Feyerherm C, Fletcher EE, Wigley DB, Dillingham MS Elife. 2022 Dec 19;11:e83409. doi: 10.7554/eLife.83409. PMID:36533901<ref>PMID:36533901</ref> | Structures of RecBCD in complex with phage-encoded inhibitor proteins reveal distinctive strategies for evasion of a bacterial immunity hub.,Wilkinson M, Wilkinson OJ, Feyerherm C, Fletcher EE, Wigley DB, Dillingham MS Elife. 2022 Dec 19;11:e83409. doi: 10.7554/eLife.83409. PMID:36533901<ref>PMID:36533901</ref> | ||
Current revision
RecBCD in complex with the phage protein gp5.9
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