... positions of the corresponding side chain, Arg220, the NADPH cofactor and the substrate analog hexosein the MUR1 structure (Fig. 11). Some of the distancesbetween these groups are rather long ... isexpected during the catalytic cycle: In the GMD reac-tion, the nicotinamide must extract hydride from the substrate C4¢, and later donate it back at C6¢.InRMDAt, the amino acid occupying the position ... GMD,both the P. aeruginosa and A. thermoaerophilus RMDsequences have gaps in the region of the RR loop, andin the His6-RMDAtstructure, the b2–b3 loop is nota-bly shorter than in GMD. The truncation...