5LKM

RadA bound to dTDP

Summary for 5LKM

• Entry DOI: 10.2210/pdb5lkm/pdb
• Descriptor: DNA repair protein RadA, THYMIDINE-5'-DIPHOSPHATE, MAGNESIUM ION (3 entities in total)
• Functional Keywords: helicase, recombination, dna-binding protein, lon-protease, dna binding protein
• Biological source: Streptococcus pneumoniae
• Total number of polymer chains: 3
• Total formula weight: 149523.46

Authors

Rapisarda, C.,Remaut, H.,Fornzes, R. (deposition date: 2016-07-22, release date: 2017-06-07, Last modification date: 2024-01-10)

Primary citation

Marie, L.,Rapisarda, C.,Morales, V.,Berge, M.,Perry, T.,Soulet, A.L.,Gruget, C.,Remaut, H.,Fronzes, R.,Polard, P.
Bacterial RadA is a DnaB-type helicase interacting with RecA to promote bidirectional D-loop extension.
Nat Commun, 8:15638-15638, 2017

PubMed Abstract: Homologous recombination (HR) is a central process of genome biology driven by a conserved recombinase, which catalyses the pairing of single-stranded DNA (ssDNA) with double-stranded DNA to generate a D-loop intermediate. Bacterial RadA is a conserved HR effector acting with RecA recombinase to promote ssDNA integration. The mechanism of this RadA-mediated assistance to RecA is unknown. Here, we report functional and structural analyses of RadA from the human pathogen Streptococcus pneumoniae. RadA is found to facilitate RecA-driven ssDNA recombination over long genomic distances during natural transformation. RadA is revealed as a hexameric DnaB-type helicase, which interacts with RecA to promote orientated unwinding of branched DNA molecules mimicking D-loop boundaries. These findings support a model of DNA branch migration in HR, relying on RecA-mediated loading of RadA hexamers on each strand of the recipient dsDNA in the D-loop, from which they migrate divergently to facilitate incorporation of invading ssDNA.

PubMed: 28561029
DOI: 10.1038/ncomms15638

Experimental method

X-RAY DIFFRACTION (3.5 Å)