Structure and flexibility of the thermophilic cold-shock protein of Thermus aquaticus.

Abstract

The thermophilic bacterium Thermus aquaticus is a well-known source of Taq polymerase. Here, we studied the structure and dynamics of the T. aquaticus cold-shock protein (Ta-Csp) to better understand its thermostability using NMR spectroscopy. We found that Ta-Csp has a five-stranded β-barrel structure with five salt bridges which are important for more rigid structure and a higher melting temperature (76 °C) of Ta-Csp compared to mesophilic and psychrophilic Csps. Microsecond to millisecond time scale exchange processes occur only at the β1-β2 surface region of the nucleic acid binding site with an average conformational exchange rate constant of 674 s(-1). The results imply that thermophilic Ta-Csp has a more rigid structure and may not need high structural flexibility to accommodate nucleic acids upon cold shock compared to its mesophile and psychrophile counterparts.

• Authors: Bonghwan Jin, Ki-Woong Jeong, Yangmee Kim
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 451 Issue 3 Pg. 402-7 (Aug 29 2014) ISSN: 1090-2104 [Electronic] United States
• PMID: 25101648 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Bacterial Proteins
• Cold Shock Proteins and Peptides

Topics

• Bacterial Proteins (chemistry)
• Circular Dichroism
• Cold Shock Proteins and Peptides (chemistry)
• Models, Molecular
• Nuclear Magnetic Resonance, Biomolecular
• Protein Conformation
• Protein Stability
• Protein Structure, Secondary
• Thermus (chemistry)