Crystal structure of human mitochondrial single-stranded DNA binding protein at 2.4 A resolution.
We solved the crystal structure of the homotetrameric single-stranded DNA binding (SSB) protein from human mitochondria at a resolution of 2.4 A. The tetramer is formed by two dimers interacting head-to-head and shows D2 symmetry. Sequence-related tetrameric SSB proteins occur in prokaryotes and eukaryotic mitochondria; this is the first report of an atomic resolution structure of this type of protein. Using biochemical data and analysis of sequence homologies, we were able to correlate the functional properties with structure. We propose that ssDNA wraps around the tetrameric HsmtSSB protein through electropositive channels guided by flexible loops.
Yang
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Department of Biochemistry and Biophysics, Washington State University, Pullman 99164-4660, USA.
Curth
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Urbanke
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Kang
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D000595:Amino Acid Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D019281:Dimerization; D006801:Humans; D046911:Macromolecular Substances; D008928:Mitochondria / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D011994:Recombinant Proteins