... D and E + F), (b) a few hydrogenbonds, and a hydrophobic interaction between A + C,B + E and D + F, and (c) electrostatic forces in thecentral channel of the hexamer between B, C and F, and ... Glu204(Fig. 3A,C), and a hydrophobic interaction betweenThr131 and Phe133 (Fig. 3D). The central channel of the hexamer is made up of two layers of electrostaticforces on top of each other, with one ... consequences of F133N and F133AmutationsGTP is an activator for all bacterial UMPKs studiedto date [5,14–17], and it was therefore tested with UpUMPK. In an assay with 1 mm UMP and ATP, theaddition of...