An Examination by Site-Directed Mutagenesis of Putative Key Residues in the Determination of Coenzyme Specificity in Clostridial NAD+-Dependent Glutamate Dehydrogenase

Figure 2

Alignment of the relevant stretch of amino acid sequence in a number of different GDHs. The arrows indicate the three positions targeted for mutagenesis in this study and the numbers in brackets the residue numbers. The abbreviated biological species are Cs Clostridium symbiosum, Cd Clostridium difficile, Pa Peptostreptococcus asaccharolyticus, Hs Halobacterium salinarum, Ec Escherichia coli, St Salmonella typhimurium, ? unidentified bacterium, Ch Chlorella sorokiniana, Nc Neurospora crassa, An Aspergillus nidulans, Sc Saccharomyces cerevisiae, So Schwanniomyces occidentalis. The coenzyme specificity of the source GDH is indicated for all the monospecific enzymes, the others being dual-specific.