Identification and nucleotide sequence of the Acinetobacter calcoaceticus encoded trpE gene

The trpE gene from Acinetobacter calcoaceticus encoding the anthranilate synthase component I was cloned, identified by deletion analysis and sequenced. It encodes a predicted polypeptide of 497 amino acids with a calculated molecular weight of 55,323. Its primary structure shows 49% identical amino acids with the enzyme from Clostridium thermocellum, 45% with that of Thermus thermophilus and only 35% with that of Escherichia coli. The codon usage of the trpE genes encoding the most homologous enzymes differs greatly indicating selection for amino acid maintainance. The homologies are clustered in the C-terminal 200 amino acids of the sequences indicating that this part is important for enzymic activity.