Cloning and Nucleotide Sequencing of the Antitumor Antibiotic C-1027 Apoprotein Gene

Abstract

The apoprotein gene for a chromoprotein antitumor antibiotic, C-1027, was cloned from the producer strain, Streptomyces globisporus C-1027, and sequenced. The process verified that ; (1) the sequence included the entire structural gene directing a precursor of the apoprotein (pre-apoprotein having Met¹-Ala³³ leader peptide ahead of the apoprotein) and flanking regions, (2) the amino acid sequence of the apoprotein deduced from the base sequence perfectly matched the one based on protein analysis, ¹⁾ (3) 3rd letters of codons were 88% G or C, while the 1st plus the 2nd letters were 63% G or C, (4) the structural gene had 57% homology with that of macromomycin apoprotein (mcmA) while the flanking regions had little homology with the corresponding ones of mcmA, except some homology at the -10th and -35th promoter regions, and (5) the gene was transcribed as a monocistronic mRNA in an early growth phase, independent of chromophore production.