Properties of lanK-based regulatory circuit involved in landomycin biosynthesis in Streptomyces cyanogenus S136.

LanK is TetR-like regulatory protein recently shown to regulate the export and glycosylation of landomycins in Streptomyces cyanogenus S136. Here, several properties of the lanK-mediated regulation were deciphered. LanK seems to function as oligomer as evident from experiments in vitro.

[The use of PCR for detecting genes that encode type I polyketide synthases in genomes of actinomycetes].

PCR screening of type I polyketidesynthase genes (PKS) was conducted in genomes of actinomycetes, producers of antibiotics. Some DNA fragments from the Streptomyces globisporus 1912 strain, a producer of a novel angucycline antibiotic landomycin E, were amplified. These fragments shared appreciable homology with type I PKS controlling the biosynthesis of polyene antibiotics (pymaricin and nistatin).

[Interspecies conjugation of Escherichia coli-Streptomyces globisporus 1912 using integrative plasmid pSET152 and its derivatives].

Streptomyces globisporus 1912 produces a novel angucycline antitumor antibiotic landomycin E (LE). To study the LE biosynthetic gene cluster in detail, a system for the conjugal transfer of the integrative plasmid pSET152 from Escherichia coli into S. globisporus 1912 has been developed.

[Activation of corneal endothelial proliferation in cancers of various sites].

90 corneas from patients, 40 to 80 years old, who had died from carcinoma of mammary gland, lungs and other organs, and 20 corneas from patients of the same age dying from cardiovascular diseases, were studied. The density of endothelial cells was significantly increased in carcinoma patients (for example, 2939 cells/mm2 versus 2160 in control at the age of 40-60 years) with a simultaneous decrease of the cell surface. There was an increase in the number of cells with a small surface and a decrease in the number of binuclear cells.