title: Evolutionary comparisons of RecA-like proteins across all major kingdoms of living organisms.
abstract: Protein sequences with similarities to Escherichia coli RecA were compared across the major kingdoms of eubacteria, archaebacteria, and eukaryotes. The archaeal sequences branch monophyletically and are most closely related to the eukaryotic paralogous Rad51 and Dmc1 groups. A multiple alignment of the sequences suggests a modular structure of RecA-like proteins consisting of distinct segments, some of which are conserved only within subgroups of sequences. The eukaryotic and archaeal sequences share an N-terminal domain which may play a role in interactions with other factors and nucleic acids. Several positions in the alignment blocks are highly conserved within the eubacteria as one group and within the eukaryotes and archaebacteria as a second group, but compared between the groups these positions display nonconservative amino acid substitutions. Conservation within the RecA-like core domain identifies possible key residues involved in ATP-induced conformational changes. We propose that RecA-like proteins derive evolutionarily from an assortment of independent domains and that the functional homologs of RecA in noneubacteria comprise an array of RecA-like proteins acting in series or cooperatively.
authors.affiliation: Department of Mathematics, Stanford University, Stanford, CA 94305-2125, USA.
authors.forename: V
authors.initials: V
authors.lastname: Brendel
authors.forename: L
authors.initials: L
authors.lastname: Brocchieri
authors.forename: S J
authors.initials: SJ
authors.lastname: Sandler
authors.forename: A J
authors.initials: AJ
authors.lastname: Clark
authors.forename: S
authors.initials: S
authors.lastname: Karlin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019843:Archaeal Proteins; D001419:Bacteria / Q000235:genetics; D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D016384:Consensus Sequence / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D029968:Escherichia coli Proteins; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D051135:Rad51 Recombinase; D011938:Rec A Recombinases / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C491059:RadA protein, E coli; C117252:RadA protein, archaeal; C100901:RadA protein, bacteria; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; D011938:Rec A Recombinases; C074556:DMC1 protein, human