4d2i
Crystal structure of the HerA hexameric DNA translocase from Sulfolobus solfataricus bound to AMP-PNP
Structural highlights
FunctionHERA_SACS2 Involved in DNA double-strand break (DSB) repair (PubMed:22135300). Acts probably with NurA to stimulate resection of the 5' strand and produce the long 3' single-strand that is required for RadA loading (By similarity). Exhibits DNA-dependent ATPase activity and DNA helicase activity (PubMed:22135300, PubMed:25420454).[UniProtKB:Q8U1P0][1] [2] Publication Abstract from PubMedThe 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. Structure of the hexameric HerA ATPase reveals a mechanism of translocation-coupled DNA-end processing in archaea.,Rzechorzek NJ, Blackwood JK, Bray SM, Maman JD, Pellegrini L, Robinson NP Nat Commun. 2014 Nov 25;5:5506. doi: 10.1038/ncomms6506. PMID:25420454[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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