Bobst EV, Bobst AM, Perrino FW, Meyer RR, Rein DC. Variability in the nucleic acid binding site size and the amount of single-stranded DNA-binding protein in Escherichia coli.
FEBS Lett 1985;
181:133-7. [PMID:
2982651 DOI:
10.1016/0014-5793(85)81128-5]
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Abstract
The Escherichia coli single-stranded DNA binding protein (SSB), essential for DNA replication, recombination and repair, can undergo a thermally induced irreversible conformational change which does not eliminate its biological activity, but changes the number of nucleotides it covers (binding site size) when binding to a single-stranded nucleic acid lattice. The binding site size of native and conformationally changed SSB was also found to be a function of the molecular mass of the polynucleotide, an observation which is unusual for single-stranded DNA binding proteins and will greatly affect the affinity relationship of this protein for nucleic acids. A radioimmunoassay used to quantitate in SSB level in cells revealed the number of SSB tetramers to be larger than initial estimates by a factor of as much as six. All these data suggest that the biological role of SSB and its mechanism of action is by far more complex than originally assumed.
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