Cloning and nucleotide sequence of the gene responsible for chlorination of tetracycline.
Two cosmid clones containing distinct types of self-defense gene of a 6-demethylchlortetracycline producer, Streptomyces aureofaciens NRRL3203, were isolated. The gene responsible for chlorination of tetracycline (chl gene) was subcloned from one of the cosmid clones by complementation of a chlorination-deficient mutant, using a gene cloning system for strain NRRL3203 developed in this study. The nucleotide sequence analysis of a 4.4-kb SacI-BamHI fragment containing the chl gene showed that the predicted product of the chl gene is a polypeptide of 452 amino acids, and that the chl gene was preceded by two open reading frames, which could endode polypeptides of 50 kDa and 32 kDa, respectively. A search for sequences homologous to these ORFs found that the former product strongly resembles that of the 6-hydroxylation enzyme for oxytetracycline biosynthesis, and that the latter product has a weak but significant similarity to the hydroxyindole O-methyltransferase of bovine pineal gland. By Northern blot analysis, these three genes were suggested to be polycistronically transcribed.
Dairi
T
T
Tokyo Research Laboratories of Kyowa Hakko Kogyo Co., Ltd., Japan.
Nakano
T
T
Aisaka
K
K
Katsumata
R
R
Hasegawa
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D002713:Chlorine / Q000378:metabolism*; D003001:Cloning, Molecular; D003360:Cosmids; D004274:DNA, Recombinant; D003707:Demeclocycline / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013304:Streptomyces aureofaciens / Q000235:genetics* / Q000378:metabolism; D013752:Tetracycline / Q000378:metabolism*; D014158:Transcription, Genetic
D004274:DNA, Recombinant; D002713:Chlorine; D003707:Demeclocycline; D013752:Tetracycline