Novel homologs of replication protein A in archaea: implications for the evolution of ssDNA-binding proteins.
In Bacteria and Eukarya, ssDNA-binding proteins are central to most aspects of DNA metabolism. Until recently, however, no counterpart of an ssDNA-binding protein had been identified in the third domain of life, Archaea. Here, we report the discovery of a novel type of ssDNA-binding protein in the genomes of several archaeons. These proteins, in contrast to all known members of this protein family, possess four conserved DNA-binding sites within a single polypeptide or, in one case, two polypeptides. This peculiar structural organization allows us to propose a model for the evolution of this class of proteins.
Section of Microbiology, University of California, Davis 95616-8665, USA.
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F
Chédin
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Seitz
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Kowalczykowski
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000502:physiology*; D001665:Binding Sites; D017124:Conserved Sequence; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D019143:Evolution, Molecular; D017017:Methanococcus / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D051716:Replication Protein A; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D019843:Archaeal Proteins; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D051716:Replication Protein A