Nucleotide and deduced amino acid sequences of nifE from Clostridium pasteurianum.

We have cloned and sequenced a DNA fragment down stream from the nifHIDK operon (1) from C. pasteurianum W5. The deduced amino acids of an ORF in this fragment of DNA shares sequence similarity of 33% with that of nifE gene from Azotobacter vinelandii (2). Therefore we designate this gene as nifE of C. pasteurianum. The identical amino acids are underlined in the figure. There was no other coding region (like nifTY in Klebsiella pneumoniae and A. vinelandii) between the coding regions of nifK and nifE. The space between nifK and nifE of C. pasteurianum is 279 base pairs. We also determined the transcription start site of nifE by primer extension method (3). The first nucleotide of the sequence shown below is the transcription start site of nifE.