2.7.1.161 Mj0056 has sequence properties intermediate between basal cradle-loop barrels and ATP-dependent riboflavin kinases. It is proposed that it represents an evolutionary bridge between the two groups of proteins 682881 2.7.1.161 Mj0056-MgCDP and Mj0056-MgCDP-FMN, in complex with natural reaction products and, Mj0056-NaCDP-PO4, with inorganic phosphate bound in a similar position as the FMN phosphate 682881 2.7.1.161 purified RbkR in complex with its specific DNA operator, X-ray diffraction structure determination and analysis. The asymmetric unit of the taRbkR-DNA-CTP complex structure contains a taRbkR dimer bound to an 18-bp RbkR site DNA 762041 2.7.1.161 structures, Mj0056-MgCDP and Mj0056-MgCDP-FMN, in complex with natural reaction products and a third, Mj0056-NaCDP-PO4, with inorganic phosphate 682881