8b1u
From Proteopedia
(Difference between revisions)
| Line 4: | Line 4: | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[8b1u]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli], [https://en.wikipedia.org/wiki/Salmonella_virus_P22 Salmonella virus P22] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8B1U OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8B1U FirstGlance]. <br> | <table><tr><td colspan='2'>[[8b1u]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli], [https://en.wikipedia.org/wiki/Salmonella_virus_P22 Salmonella virus P22] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8B1U OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8B1U FirstGlance]. <br> | ||
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ANP:PHOSPHOAMINOPHOSPHONIC+ACID-ADENYLATE+ESTER'>ANP</scene>, <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]] 3.8Å</td></tr> |
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ANP:PHOSPHOAMINOPHOSPHONIC+ACID-ADENYLATE+ESTER'>ANP</scene>, <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=8b1u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8b1u OCA], [https://pdbe.org/8b1u PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8b1u RCSB], [https://www.ebi.ac.uk/pdbsum/8b1u PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8b1u 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=8b1u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8b1u OCA], [https://pdbe.org/8b1u PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8b1u RCSB], [https://www.ebi.ac.uk/pdbsum/8b1u PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8b1u ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
| - | [https://www.uniprot.org/uniprot/ | + | [https://www.uniprot.org/uniprot/RECB_ECOLI RECB_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 contributes ATPase, 3'-5' helicase, exonuclease activity and loads RecA onto ssDNA. The RecBC complex requires the RecD subunit for nuclease activity, but can translocate along ssDNA in both directions.<ref>PMID:10197988</ref> <ref>PMID:10518611</ref> <ref>PMID:10766864</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:16388588</ref> <ref>PMID:18079176</ref> <ref>PMID:20852646</ref> <ref>PMID:23851395</ref> <ref>PMID:25073102</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-DNA in complex with the phage protein Abc2 and host PpiB
| |||||||||||
