Cloning of cDNA encoding the bifunctional dehydroquinase·shikimate dehydrogenase of aromatic-amino-acid biosynthesis in Nicotiana tabacum

Abstract

Nicotiana tabacum cDNA encoding a bifunctional protein having catalytic domains for dehydroquinase and shikimate dehydrogenase was cloned and sequenced. Complementation of Escherichia coli aroD and aroE auxotrophs was successful. Amino acid sequencing located the N-terminus of the mature protein. The two catalytic domains exhibited greater amino acid identity with prokaryote homologues than with yeast and fungal homologues.