Nucleotide sequence analysis of the carbomycin biosynthetic genes including the 3-O-acyltransferase gene from Streptomyces thermotolerans.
A 3.2-kb DNA fragment of the carbomycin biosynthetic region including the 3-O-acyltransferase gene (acyA) from Streptomyces thermotolerans was sequenced, and four ORFs were found in the fragment. The second ORF, designated ORF-A, was transcribed in the opposite direction to the other three ORFs. The first ORF was identified as carA, a gene for carbomycin resistance. The amino acid sequence of ORF-A was homologous to proteins of the cytochrome P-450 family. Streptomyces lividans transformed with pCB20, in which ORF-A was subcloned, epoxidized carbomycin B at its C-12, 13 positions, thus producing carbomycin A. The third ORF, the amino acid sequence of which showed a homology to macrolide antibiotics O-acyltransferases was identified as acyA. The last ORF (ORF-B), which starts just 3 bp downstream from the TGA termination codon of acyA, was thought to be a carbomycin 4-O-methyltransferase gene, because the amino acid sequence deduced from ORF-B showed high homology to a putative midecamycin 4-O-methyltransferase encoded on mdmC.
Arisawa
A
A
Mercian Corporation, Central Research Laboratories, Kanagawa, Japan.
Tsunekawa
H
H
Okamura
K
K
Okamoto
R
R
D000123:Acetyltransferases / Q000235:genetics*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D002240:Carbohydrate Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D007933:Leucomycins / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics*
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007933:Leucomycins; C059423:carbomycin; D000123:Acetyltransferases; C093957:carbomycin 3-O-acetyltransferase