The Huck Institutes of the Life Sciences

Mechanistic characterization of the 5'-triphosphate-dependent activation of PKR: Lack of 5'-end nucleobase specificity, evidence for a distinct triphosphate binding site, and a critical role for the dsRBD

Toroney, R., Hull, C. M., Sokoloski, J. E., and Bevilacqua, P. C. (2012) RNA 18, 1862-1874.

This study shows that PKR binds tightly and specifically to ATP (B) but not to CTP, GTP, or UTP (A).

ATP into PKR (B)
Kd = 19.0 µM

This is important for identifying the number of triphosphate binding sites and their locations on PKR, which relates to its function in innate immunity.

We used auto-ITC to measure the thermodynamic parameters for NTP binding to PKR.

Toroney et al.