Nncleotide sequence of thefnrgene and primary structure of the Fnr protein ofEschertchla coli

Abstract

The nucleotide sequence of a 1.64 kb fragment of E. coll DNA containing the fnr gene (regulatory gene for fumarate and nitrate reduction) was determined using the dideoxy chain termination method. The fnr coding region (750 bp) was identified, and the initiation and termination points of fnr transcription were located by RNA:DNA hybridisation with single-stranded Ml3 probes. The DNA fragment also contained the 5′ end of a separately transcribed gene of unknown function. The deduced molecular weight (27947) of the Fnr protein was in agreement with that of the protein identified by the maxicell procedure, and the primary structure contained regions of homology with several transcriptional regulator proteins.