Structure of a hexameric form of RadA recombinase from Methanococcus voltae.
Archaeal RadA proteins are close homologues of eukaryal Rad51 and DMC1 proteins and are remote homologues of bacterial RecA proteins. For the repair of double-stranded breaks in DNA, these recombinases promote a pivotal strand-exchange reaction between homologous single-stranded and double-stranded DNA substrates. This DNA-repair function also plays a key role in the resistance of cancer cells to chemotherapy and radiotherapy and in the resistance of bacterial cells to antibiotics. A hexameric form of a truncated Methanococcus voltae RadA protein devoid of its small N-terminal domain has been crystallized. The RadA hexamers further assemble into two-ringed assemblies. Similar assemblies can be observed in the crystals of Pyrococcus furiosus RadA and Homo sapiens DMC1. In all of these two-ringed assemblies the DNA-interacting L1 region of each protomer points inward towards the centre, creating a highly positively charged locus. The electrostatic characteristics of the central channels can be utilized in the design of novel recombinase inhibitors.
Department of Biochemistry, University of Saskatchewan, 107 Wiggins Road, Suite A3, Saskatoon, Sasktchewan S7N 5E5, Canada.
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D019843:Archaeal Proteins / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D017017:Methanococcus / Q000737:chemistry*; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D055672:Static Electricity
D019843:Archaeal Proteins; D004268:DNA-Binding Proteins; C117252:RadA protein, archaeal