title: Structural conservation of RecF and Rad50: implications for DNA recognition and RecF function.
abstract: RecF, together with RecO and RecR, belongs to a ubiquitous group of recombination mediators (RMs) that includes eukaryotic proteins such as Rad52 and BRCA2. RMs help maintain genome stability in the presence of DNA damage by loading RecA-like recombinases and displacing single-stranded DNA-binding proteins. Here, we present the crystal structure of RecF from Deinococcus radiodurans. RecF exhibits a high degree of structural similarity with the head domain of Rad50, but lacks its long coiled-coil region. The structural homology between RecF and Rad50 is extensive, encompassing the ATPase subdomain and the so-called 'Lobe II' subdomain of Rad50. The pronounced structural conservation between bacterial RecF and evolutionarily diverged eukaryotic Rad50 implies a conserved mechanism of DNA binding and recognition of the boundaries of double-stranded DNA regions. The RecF structure, mutagenesis of conserved motifs and ATP-dependent dimerization of RecF are discussed with respect to its role in promoting presynaptic complex formation at DNA damage sites.
authors.affiliation: Edward A Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, MO 63104, USA.
authors.forename: Olga
authors.initials: O
authors.lastname: Koroleva
authors.forename: Nodar
authors.initials: N
authors.lastname: Makharashvili
authors.forename: Charmain T
authors.initials: CT
authors.lastname: Courcelle
authors.forename: Justin
authors.initials: J
authors.lastname: Courcelle
authors.forename: Sergey
authors.initials: S
authors.lastname: Korolev
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D003460:Crystallization; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D034301:Deinococcus / Q000235:genetics*; D019281:Dimerization; D004706:Endodeoxyribonucleases / Q000235:genetics; D019143:Evolution, Molecular; D005090:Exodeoxyribonucleases / Q000235:genetics; D008958:Models, Molecular; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066218:recF protein, Bacteria; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; C415984:Rad50 protein, archaeal