   2.4.1.12 | cyclic-3',5'-diguanylate |
activates cellulose synthesis allosterically and binds BcsA-B with high affinity. The tight association of BcsA's PilZ and GT domains suggests that cyclic-3',5'-diguanylate controls the accessibility of the GT active site. Titrating UDP-Glc at different cyclic-3',5'-diguanylate concentrations shows that the maximum catalytic activity achieved depends on the overall c-di-GMP concentration, whereas the apparent affinity for UDP-Glc remains within 0.1-1.0 mM, comparable with the Km of 0.5 mM for UDP-Glc determined in the presence of 0.030 mM cyclic-3',5'-diguanylate. The cyclic-3',5'-diguanylate binding PilZ domain of cellulose synthase is a part of the catalytic BcsA subunit. Cyclic-3',5'-diguanylate does not alter BcsA's apparent affinity for UDP-Glc, yet it increases BcsA's apparent catalytic rate in vitro at least 10fold |
737161 |
