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J Biol Chem
2019 Mar 15;29411:4137-4144. doi: 10.1074/jbc.RA118.007048.
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A stable tetramer is not the only oligomeric state that mitochondrial single-stranded DNA binding proteins can adopt.
Singh SP
,
Kukshal V
,
Galletto R
.
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Mitochondrial single-stranded DNA (ssDNA)-binding proteins (mtSSBs) are required for mitochondrial DNA replication and stability and are generally assumed to form homotetramers, and this species is proposed to be the one active for ssDNA binding. However, we recently reported that the mtSSB from Saccharomyces cerevisiae (ScRim1) forms homotetramers at high protein concentrations, whereas at low protein concentrations, it dissociates into dimers that bind ssDNA with high affinity. In this work, using a combination of analytical ultracentrifugation techniques and DNA binding experiments with fluorescently labeled DNA oligonucleotides, we tested whether the ability of ScRim1 to form dimers is unique among mtSSBs. Although human mtSSBs and those from Schizosaccharomyces pombe, Xenopus laevis, and Xenopus tropicalis formed stable homotetramers, the mtSSBs from Candida albicans and Candida parapsilosis formed stable homodimers. Moreover, the mtSSBs from Candida nivariensis and Candida castellii formed tetramers at high protein concentrations, whereas at low protein concentrations, they formed dimers, as did ScRim1. Mutational studies revealed that the ability to form either stable tetramers or dimers depended on a complex interplay of more than one amino acid at the dimer-dimer interface and the C-terminal unstructured tail. In conclusion, our findings indicate that mtSSBs can adopt different oligomeric states, ranging from stable tetramers to stable dimers, and suggest that a dimer of mtSSB may be a physiologically relevant species that binds to ssDNA in some yeast species.
Antony,
Plasmodium falciparum SSB tetramer binds single-stranded DNA only in a fully wrapped mode.
2012, Pubmed
Antony,
Plasmodium falciparum SSB tetramer binds single-stranded DNA only in a fully wrapped mode.
2012,
Pubmed
Antony,
Plasmodium falciparum SSB tetramer wraps single-stranded DNA with similar topology but opposite polarity to E. coli SSB.
2012,
Pubmed
Barat,
A DNA binding protein from Xenopus laevis oocyte mitochondria.
1981,
Pubmed
,
Xenbase
Bujalowski,
Monomer-tetramer equilibrium of the Escherichia coli ssb-1 mutant single strand binding protein.
1991,
Pubmed
Bujalowski,
Escherichia coli single-strand binding protein forms multiple, distinct complexes with single-stranded DNA.
1986,
Pubmed
Bujalowski,
Binding mode transitions of Escherichia coli single strand binding protein-single-stranded DNA complexes. Cation, anion, pH, and binding density effects.
1988,
Pubmed
Carlini,
Identification of amino acids stabilizing the tetramerization of the single stranded DNA binding protein from Escherichia coli.
1998,
Pubmed
Khamis,
Investigation of the role of individual tryptophan residues in the binding of Escherichia coli single-stranded DNA binding protein to single-stranded polynucleotides. A study by optical detection of magnetic resonance and site-selected mutagenesis.
1987,
Pubmed
Khamis,
Role of tryptophan 54 in the binding of E. coli single-stranded DNA-binding protein to single-stranded polynucleotides.
1987,
Pubmed
Landwehr,
A dimeric mutant of the homotetrameric single-stranded DNA binding protein from Escherichia coli.
2002,
Pubmed
Lohman,
Escherichia coli single-stranded DNA-binding protein: multiple DNA-binding modes and cooperativities.
1994,
Pubmed
Lohman,
Two binding modes in Escherichia coli single strand binding protein-single stranded DNA complexes. Modulation by NaCl concentration.
1985,
Pubmed
Lohman,
Interactions of the E. coli single strand binding (SSB) protein with ss nucleic acids. Binding mode transitions and equilibrium binding studies.
1988,
Pubmed
Nishio,
Gene structure and biochemical characterization of mitochondrial single-stranded DNA binding protein from Schizosaccharomyces pombe.
2006,
Pubmed
Nosek,
Mitochondrial telomere-binding protein from Candida parapsilosis suggests an evolutionary adaptation of a nonspecific single-stranded DNA-binding protein.
1999,
Pubmed
Qian,
The human mitochondrial single-stranded DNA-binding protein displays distinct kinetics and thermodynamics of DNA binding and exchange.
2017,
Pubmed
Raghunathan,
Crystal structure of the homo-tetrameric DNA binding domain of Escherichia coli single-stranded DNA-binding protein determined by multiwavelength x-ray diffraction on the selenomethionyl protein at 2.9-A resolution.
1997,
Pubmed
Ramanagoudr-Bhojappa,
Physical and functional interaction between yeast Pif1 helicase and Rim1 single-stranded DNA binding protein.
2013,
Pubmed
Roy,
Dynamic structural rearrangements between DNA binding modes of E. coli SSB protein.
2007,
Pubmed
Singh,
The mitochondrial single-stranded DNA binding protein from S. cerevisiae, Rim1, does not form stable homo-tetramers and binds DNA as a dimer of dimers.
2018,
Pubmed
Tomaska,
Electron microscopic analysis supports a dual role for the mitochondrial telomere-binding protein of Candida parapsilosis.
2001,
Pubmed
Tomáska,
Identification of a putative mitochondrial telomere-binding protein of the yeast Candida parapsilosis.
1997,
Pubmed
Van Dyck,
A single-stranded DNA binding protein required for mitochondrial DNA replication in S. cerevisiae is homologous to E. coli SSB.
1992,
Pubmed
,
Xenbase
Webster,
A common core for binding single-stranded DNA: structural comparison of the single-stranded DNA-binding proteins (SSB) from E. coli and human mitochondria.
1997,
Pubmed
Wong,
Physical and functional interactions between human mitochondrial single-stranded DNA-binding protein and tumour suppressor p53.
2009,
Pubmed
Yang,
Crystal structure of human mitochondrial single-stranded DNA binding protein at 2.4 A resolution.
1997,
Pubmed
