Download MendeleyStructure of the Hexameric Hera ATPase Reveals a Mechanism of Translocation-Coupled DNA-End Processing in Archaea
Rzechorzek, N.J., Blackwood, J.K., Bray, S.M., Maman, J.D., Pellegrini, L., Robinson, N.P.(2014) Nat Commun 5: 5506
- PubMed: 25420454
- DOI: https://doi.org/10.1038/ncomms6506
- Primary Citation of Related Structures:
4D2I - PubMed Abstract:
The HerA ATPase cooperates with the NurA nuclease and the Mre11-Rad50 complex for the repair of double-strand DNA breaks in thermophilic archaea. Here we extend our structural knowledge of this minimal end-resection apparatus by presenting the first crystal structure of hexameric HerA. The full-length structure visualizes at atomic resolution the N-terminal HerA-ATP synthase domain and a conserved C-terminal extension, which acts as a physical brace between adjacent protomers. The brace also interacts in trans with nucleotide-binding residues of the neighbouring subunit. Our observations support a model in which the coaxial interaction of the HerA ring with the toroidal NurA dimer generates a continuous channel traversing the complex. HerA-driven translocation would propel the DNA towards the narrow annulus of NurA, leading to duplex melting and nucleolytic digestion. This system differs substantially from the bacterial end-resection paradigms. Our findings suggest a novel mode of DNA-end processing by this integrated archaeal helicase-nuclease machine.
Organizational Affiliation:
Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK.
