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M A Bychkova

Publications and source records attributed to M A Bychkova.

12 recordsLinked to original sources

[Site-specific restrictases from Bacillus thuringiensis var. Kumantoensis].

The efficiency of bacteriophages CP-54 and CP-55 plating on Bacillus thuringiensis var. kumantoensis H18 (Kum) is decreased about 10-fold as compared with the efficiency of plating on Bacillus thuringiensis var. galleriae H5 (Gal). Bacteriophages having propagated for one cycle in Kum cells might be further grown in this strain without growth restriction. Two site-specific restriction enzymes isolated from Bacillus thuringiensis var. kumantoensis were designated BtkI and BtkII. The endonuclease BtkI recognises the same nucleotide sequence CGCG in DNA as recognised by the restriction endonuclease FnuDII; BtkII recognises the same nucleotide sequence GATC as the endonuclease Sau3A.

Bacillus thuringiensis↗

[Cloning of the structural gene for diphtheria toxin from Corynebacterium diphtheriae PW8 and expression of its deletion derivative in E. coli].

The coding region of diphtheria toxin gene from Corynebacterium diphtheriae PW8 was cloned in Escherichia coli on pUC19 plasmid. 5' end of the gene was deleted. The deleted gene codes for a toxin like protein truncated for 36 N-terminal aminoacids. The modified gene was fused with 5' terminal part of the lacZ gene on pUC19 plasmid having kept the translational frame intact. The hybrid gene transcription depends on lacP promoter, Mr of the resulting toxoid is 54,000. The toxoid is devoid of ADP-ribosyltransferase activity peculiar for diphtheria toxin and thus is not toxic. The constructed version of the toxin gene can be used for production of diphtheria anatoxin which does not require to be inactivated by formalin.

Chromosome Deletion↗