Krajewski, Wojciech W. and Fu, X. and Wilkinson, M. and Cronin, N.B. and Dillingham, M.S. and Wigley, D.B. (2014) Structural basis for translocation by AddAB helicase–nuclease and its arrest at χ sites. Nature 508 , pp. 416-419. ISSN 0028-0836.
Abstract
In bacterial cells, processing of double-stranded DNA breaks for repair by homologous recombination is dependent upon the recombination hotspot sequence χ (Chi)1, 2 and is catalysed by either an AddAB- or RecBCD-type helicase–nuclease (reviewed in refs 3, 4). These enzyme complexes unwind and digest the DNA duplex from the broken end until they encounter a χ sequence5, whereupon they produce a 3′ single-stranded DNA tail onto which they initiate loading of the RecA protein6. Consequently, regulation of the AddAB/RecBCD complex by χ is a key control point in DNA repair and other processes involving genetic recombination. Here we report crystal structures of Bacillus subtilis AddAB in complex with different χ-containing DNA substrates either with or without a non-hydrolysable ATP analogue. Comparison of these structures suggests a mechanism for DNA translocation and unwinding, suggests how the enzyme binds specifically to χ sequences, and explains how χ recognition leads to the arrest of AddAB (and RecBCD) translocation that is observed in single-molecule experiments7, 8, 9.
Metadata
| Item Type: | Article |
|---|---|
| School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
| Depositing User: | Administrator |
| Date Deposited: | 31 Mar 2014 09:27 |
| Last Modified: | 02 Aug 2023 17:10 |
| URI: | https://eprints.bbk.ac.uk/id/eprint/9477 |
Statistics
Additional statistics are available via IRStats2.
Archive Staff Only (login required)
