Fig. 9: Enzyme kinetics of DgcR.

a–c Enzymatic progress curves of wild-type DgcR and inhibition relieved mutant DgcR’ in the native and in the activated (indicated by asterisk) state. Experiments were performed with 5 μM enzyme and 500 μM GTP substrate concentrations. Symbols denote experimental values, continuous lines represent fit of the kinetic model shown in panel d to the data with parameters listed in Supplementary Table 2. a Progress curve of c-di-GMP production catalysed by DgcR* as measured by conventional IEC. b Progress curves as measured by oIEC catalysed with the indicated DgcR variants/states. c Zoom- in of b. d Kinetic model of diguanylate cyclase activity controlled by non-competitive product binding. Substrate (S) binding to the dimeric enzyme (EE) is modelled with the equilibrium dissociation constant K_d and assumed to be unaffected by the presence of S in the second binding site or of product (P) in the allosteric site. Product binding is modelled kinetically with rate constants k_on and k_off. Note that the model considers simply one instead of four product binding sites on the enzyme. Only the Michaelis–Menten complex with two bound substrate molecules and no bound product (SEES) is competent to catalyse the S + S → P condensation reaction (with turn-over number k_cat). Source data are provided as a Source Data file.