Nucleotide sequence of plasmid NAH7 gene nahR and DNA binding of the nahR product.
The nah and sal operons of the 80-kilobase-pair (kb) NAH7 plasmid specify catabolism of naphthalene and salicylate under positive regulation by gene nahR. A 1.75-kb fragment (PstI-HindIII) cloned into the pCP13 derivative of vector RK2 complemented in trans five nahR mutations. The fragment sequence contained a 1,122-base-pair open reading frame with a predicted sequence of 374 residues that was rich in basic amino acids with regions similar to known DNA-binding proteins. Clones from the nahR gene region were expressed in mexicells. Plasmid pY1923, carrying the 1.75-kb PstI-HindIII fragment, expressed a protein of Mr ca. 35,000 which bound to the upstream region of gene nahR in a gel electrophoresis DNA-binding assay. Other clones expressed proteins of currently unknown function; pY1311, with the 1.1-kb HindIII fragment, produced a polypeptide with an Mr of 23,000, and pY1812, with the 1.2-kb PstI-SphI fragment, produced a polypeptide (Mr 41,000) which appeared to be a fused nahR-lacZ product.
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Department of Biochemistry, University of Illinois, Urbana 61801.
Ghosal
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Gunsalus
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D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics*; D005796:Genes; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D009281:Naphthalenes / Q000378:metabolism; D010957:Plasmids; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D001426:Bacterial Proteins; D009281:Naphthalenes