Microcalorimetric measurements were performed using a NanoDSC microcalorimeter (Calorimetry Science Corporation, USA). Samples containing 1.5 mg/ml SSB in 50 mM potassium AZ 628 phosphate buffer pH 7.5 and 0.1 M NaCl were analyzed. The calorimetric scans were carried out between 20 and 130°C with a scan rate of 1°C/min (Figure 6). The reversibility of the transition was checked

by cooling and reheating the same sample with the scan rate of 1°C/min. Results from the DSC measurements were analyzed with the NanoAnalyze Software V 1.1 (TA Instruments, USA). Nucleotide sequence accession number The nucleotide sequences of the ssb genes of T. maritima and T. neapolitana are available in the GenBank database under the accession numbers

AAD35689[20] and GU125728, respectively. Acknowledgements This work was supported by the Gdańsk University of Technology. We thank the Laboratory of Intermolecular Interaction of Biomacromolecules at the Centre of Excellence ChemBioFarm for allowing access to the NanoDSC microcalorimeter used in this work. SBI-0206965 References 1. Greipel J, Urbanke C, Maass G: The single-stranded DNA binding protein of Escherichia coli . Physicochemical properties and biological functions. In Protein-Nucleic Acid Interaction. Edited by: Saenger W, Heinemann U. London: Macmillan; 1989:61–86. 2. Alani E, Thresher R, Griffith JD, Kolodner RD: Characterization of DNA-binding and strand-exchange stimulation properties of y-RPA, a yeast single-strand-DNA-binding Calpain protein. J Mol Biol 1992, 227:54–71.PubMedCrossRef 3. Lohman TM, Overman LB: Two binding modes in Escherichia coli single strand binding protein-single stranded DNA complexes. Modulation by NaCl concentration. J Biol Chem 1985, 260:3594–3603.PubMed 4. Meyer RR, Laine PS: The single-stranded DNA-binding

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