Crystal structure of archaeal recombinase RADA: a snapshot of its extended conformation.
Homologous recombination of DNA plays crucial roles in repairing severe DNA damage and in generating genetic diversity. The process is facilitated by a superfamily of recombinases: bacterial RecA, archaeal RadA and Rad51, and eukaryal Rad51 and DMC1. These recombinases share a common ATP-dependent filamentous quaternary structure for binding DNA and facilitating strand exchange. We have determined the crystal structure of Methanococcus voltae RadA in complex with the ATP analog AMP-PNP at 2.0 A resolution. The RadA filament is a 106.7 A pitch helix with six subunits per turn. The DNA binding loops L1 and L2 are located in close proximity to the filament axis. The ATP analog is buried between two RadA subunits, a feature similar to that of the active filament of Escherichia coli RecA revealed by electron microscopy. The disposition of the N-terminal domain suggests a role of the Helix-hairpin-Helix motif in binding double-stranded DNA.
Department of Biochemistry, University of Saskatchewan, A3 Health Sciences Building, 107 Wiggins Road, Saskatoon, Saskatchewan, Canada S7N 5E5.
Yan
Y
Wu
Yujiong
Y
He
Ignace A
IA
Moya
Xinguo
X
Qian
Yu
Y
Luo
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004265:DNA Helicases / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry*; D017017:Methanococcus / Q000737:chemistry / Q000201:enzymology; D008969:Molecular Sequence Data; D011487:Protein Conformation; D013997:Time Factors
D019843:Archaeal Proteins; D004268:DNA-Binding Proteins; C117252:RadA protein, archaeal; D000251:Adenosine Triphosphatases; D004265:DNA Helicases