The interaction of hyperthermophilic TATA-box binding protein with single-stranded DNA is entropically favorable and exhibits a large negative heat capacity change at high salt concentration.
We have investigated the thermodynamics of the interaction between the TATA-box-binding protein from Pyrococcus horikoshii (PhoTBP) and its target DNA (TATA-1). The interaction between PhoTBP and double-stranded DNA (dsDNA) is entropically favorable and enthalpically unfavorable. The thermodynamic parameters for TATA-1 duplex formation in the presence of PhoTBP, that is, ternary PhoTBP-dsDNA complexation, are similar to those for TATA-1 duplex formation, which is enthalpically favorable. Surface plasmon resonance analysis indicates that the interaction between PhoTBP and single-stranded DNA (ssDNA) of TATA-1 is entropy driven and has a large negative heat capacity change (-1.19 kcal mol(-1) K(-1)) at high salt concentration (800 mM NaCl). These results suggest that the favorable entropic effect corresponding to the interaction between PhoTBP and dsDNA is due not to ternary complexation but to the interaction between PhoTBP and ssDNA. This report is the first to describe the thermodynamics of the interaction between TBP and ssDNA.
Nagatoishi
Satoru
S
Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
Tanaka
Yoshikazu
Y
Kudou
Motonori
M
Tsumoto
Kouhei
K
D002151:Calorimetry; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D009994:Osmolar Concentration; D043902:Pyrococcus horikoshii / Q000235:genetics; D012965:Sodium Chloride / Q000737:chemistry*; D020349:Surface Plasmon Resonance; D016385:TATA Box; D035181:TATA-Box Binding Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D013816:Thermodynamics
D004277:DNA, Single-Stranded; D035181:TATA-Box Binding Protein; D012965:Sodium Chloride