Revealing the Structural Contributions to Thermal Adaptation of the TATA-Box Binding Protein: Molecular Dynamics and QSPR Analyses

The TATA-box binding protein (TBP) is an important element of the transcription machinery in archaea and eukaryotic organisms. TBP is expressed in organisms adapted to different temperatures, indicating a robust structure, and experimental studies have shown that the mid-unfolding temperature (Tm) of TBP is directly correlated with the optimal growth temperature (OGT) of the organism. To understand which are the relevant structural requirements for its stability, we present the first structural and dynamic computational study of TBPs, combining molecular dynamics (MD) simulations and a quantitative structure-property relationship (QSPR) over a set of TBPs of organisms adapted to different temperatures. We found that the main structural properties of TBP used to adapt to high temperatures are an increase in the ease of desolvation of charged residues at the surface, an increase in the local resiliency, the presence of Leu clusters in the protein core, and an increase in the loss of hydrophobic packing in the N-terminal subdomain. In view of our results, we consider that TBP is a good model to study thermal adaptation, and our analysis opens the possibility of performing protein engineering on TBPs to study transcription at high or low temperatures.