Disease relevance of TTC1191

• Stability parameters for individual residues in Thermus thermophilus cysteine-free RNase H were determined by native state hydrogen exchange, thus providing a unique comparison of regional thermodynamics between thermophilic and mesophilic homologues [1].
• E. coli strain MIC3001, which shows an RNase H-dependent, temperature-sensitive growth phenotype, was used for this purpose [2].

High impact information on TTC1191

• As an initial step to elucidate the stabilization mechanism of the thermophilic RNase H, we examined whether certain regions in its amino acid sequence confer the thermostability [3].
• A Gly residue inserted between alpha-helices B and C appears to relieve unfavorable interactions in the transition state and alternate conformer(s) and represents an important adaptation to adjust conformational changes within RNase H for activity at high temperatures [4].
• Furthermore, heat treatment of the fusion enzyme showed that it was stable as a tetramer at 65 degrees C. The fusion enzyme was shown to have both biotin binding and RNase H catalytic properties [5].
• A streptavidin-RNase H gene fusion was constructed by cloning the Thermus thermophilus RNase H coding sequence in the streptavidin expression vector pTSA18F [5].

References