Nucleotide sequence of the gene coding for the large subunit of ribonucleotide reductase ofEscherichia coli. Correction

The nucleotide sequence of the nrdA gene of Escherichia coli. coding for the large subunit of ribonucleotide reductase, was originally published by Carlson et al. (1). However, the published nucleotide sequence of the nrdA gene is afflicted with scattered errors leading to stretches of frame-shifts, which have severe consequences for the deduced protein sequence. The difference in amino acid composition between the corrected and the previously deduced sequence is 20%. We have determined the nucleotide sequence of the nrdA gene in 3 different random point mutants (2), and 5 different oligonucleotide-directed mutants (Aberg, A., in preparation), in addition to the wild-type gene (Fig. 1). The corrected length of the gene is 2286 bp. The deduced polypeptide is 761 amino acid residues, i.e. 17 residues shorter than earlier stated, because the corrected sequence has an in-frame UGA stopcodon 52 nucleotides upstream the previously published (1) UAG stop-codon. In addition the deduced amino acid composition (Fig. 1) corresponds within 5% to that obtained previously with the intact protein (3). The deduced composition of the former sequence (1) differed by 19% from the analytical data.