A cloned ompR-like gene of Streptomyces lividans 66 suppresses defective melC1, a putative copper-transfer gene.
Expression of tyrosinase in Streptomyces requires functional MelC1 protein, which is postulated to transfer copper to apotyrosinase. We have previously isolated a mutant of Streptomyces lividans, HT32, that phenotypically suppressed mutations in cloned melC1 (H.-C. Tseng and C. W. Chen, in preparation). Plasmid pLUS132, containing an ATG to ATA transition at the initiation codon of melC1, was used for cloning the suppressor gene from HT32. A 1687 bp suppressor DNA was isolated that contained two characteristic Streptomyces coding sequences: a 217-amino-acid open reading frame (cutR) and a truncated open reading frame (cutS) downstream. Subcloning analysis attributed the phenotypic suppression activity to the putative cutR gene from HT32. The putative CutR exhibited similarity to the response regulator OmpR of the osmoregulatory signal-transduction system in Escherichia coli. The truncated CutS resembled, to a lesser degree, the N-terminus of EnvZ, the histidine protein kinase counterpart of OmpR. DNA hybridizing to the cloned cutR-cutS sequence was detected in 16 other Streptomyces species. We postulate that the putative cutR-cutS operon regulates copper metabolism in Streptomyces.
Tseng
H C
HC
Institute of Microbiology and Immunology, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China.
Chen
C W
CW
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003062:Codon; D003300:Copper / Q000378:metabolism*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D014442:Monophenol Monooxygenase / Q000378:metabolism; D009097:Multienzyme Complexes; D016366:Open Reading Frames; D009876:Operon; D010641:Phenotype; D015398:Signal Transduction; D013045:Species Specificity; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism; D013489:Suppression, Genetic; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D003062:Codon; C103591:CutR protein, Streptomyces sp.; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D014157:Transcription Factors; D003300:Copper; D014442:Monophenol Monooxygenase; C057843:envZ protein, E coli