A SECRET WEAPON FOR PKRRATING

3B). R526 from your loop between αJ and αI anchors the C-terminal part of the activation loop by forming a salt bridge with E458 at The bottom of αEF. Q459 stabilizes the HRD motif by a hydrogen bond to the main chain carbonyl of R413. The suggestion of your activation section is stabilized by a hydrogen bond involving Y454 and E480 from αfile.