The discovery of four distinct glutamate dehydrogenase genes in a strain of Halobacterium salinarum.

In earlier work, two glutamate dehydrogenase (GDH) proteins were purified from a strain of the halophilic archaeon Halobacterium salinarum (NRC-36014). One of these, an NAD+-specific enzyme, was matched to a cloned gene from H. salinarum (GenBank accession number: X63837 S75579) by sequencing peptide fragments.

Glutamate dehydrogenase of Halobacterium salinarum: evidence that the gene sequence currently assigned to the NADP+-dependent enzyme is in fact that of the NAD+-dependent glutamate dehydrogenase.

A GDH gene from Halobacterium salinarum has been cloned and sequenced and the publication assigns the sequence to the NADP+-glutamate dehydrogenase of this organism. We have expressed this gene in Escherichia coli and find that it encodes an NAD+-dependent glutamate dehydrogenase without activity towards NADP+. Further, peptide sequence from the two corresponding proteins supports the view that the deposited sequence is indeed that of the NAD+-dependent glutamate dehydrogenase.