A SIMPLE KEY FOR PKRRATING UNVEILED

3B). R526 from the loop in between αJ and αI anchors the C-terminal portion of the activation loop by forming a salt bridge with E458 at the base of αEF. Q459 stabilizes the HRD motif by a hydrogen bond to the most crucial chain carbonyl of R413. The tip on the activation section is stabilized by a hydrogen bond amongst Y454 and E480 from αfile