FIELD: biotechnology, biochemistry, genetic and protein engineering. SUBSTANCE: recombinant plasmid DNA pERTPHO1 encoding amino acid sequence of E. coli thymidine phosphorylase comprises Nde I/Sal I fragment of plasmid DNA pET20b(+) containing promoter and terminator of RNA-polymerase T7, enhancer of translation of gene 10 of phase T7, gene of β-lactamase and Nde I/Sal I-fragment of DNA containing a gene sequence encoding Escherichia coli thymidine phosphorylase adapted to these sites. The strain-producer of E. coli BL21(DE3)/pERTPHO1 is obtained by transformation of competent cells E. coli BL21(DE3) with plasmid pERTPHO1. The strain-producer E. coli BL21(DE3)/pERTPHO1 is grown on rich medium (YT-, LB-broth and others) (or induced with isopropylthio-β-D-galactoside and grown again) up to the attainment of maximal density of bacterial culture. Thymidine phosphorylase is isolated from cells of the producer after disruption of grown cells by one of conventional methods. Invention ensures to obtain recombinant thymidine phosphorylase with high yield and by simplified technology. EFFECT: improved method of preparing, increased yield. 3 cl, 1 dwg, 3 ex
