Overexpression, purification and crystallization of a thermostable DNA ligase from the archaeon Thermococcus sp. 1519.

DNA ligases catalyze the sealing of 5'-phosphate and 3'-hydroxyl termini at single-strand breaks in double-stranded DNA and their function is essential to maintain the integrity of the genome in DNA metabolism. An ATP-dependent DNA ligase from the archaeon Thermococcus sp. 1519 was overexpressed, purified and crystallized.

[Isolation and characteristics of new thermostable DNA ligase from archaea of the genus Thermococcus].

The DNA ligase gene from thermophilic archaea of the genus Thermococcus (strain 1519) was identified and sequenced in the polymerase chain reaction. The recombinant enzyme LigTh1519 was expressed in Escherichia coli, purified, and characterized. LigTh1519 was capable of ligating the cohesive ends and single-strand breaks in double-stranded DNA (ATP as a cofactor).

Tightly regulated, high-level expression from controlled copy number vectors based on the replicon of temperate phage N15.

A new Escherichia coli host/vector system has been developed to allow a dual regulation of both the plasmid copy number and gene expression. The new pN15E vectors are low copy number plasmids based on the replicon of temperate phage N15, comprising the repA replicase gene and cB repressor gene, controlling the plasmid copy number. Regulation of pN15E copy number is achieved through arabinose-inducible expression of phage N15 antirepressor protein, AntA, whose gene was integrated into the chromosome of the host strain under control of the PBAD promoter.

[Suprapyloric resection of stomach in patients with ulcer disease].

Suprapyloric transversal resection of the stomach is one of relatively sparing methods of surgical treatment for ulcerative disease. In Medical Centre of "VAZ", suprapyloric resection of the stomach was carried out as a method of treatment of gastric ulcer in 181 patients (study group) and 139 patients underwent resection 2/3 of the stomach by Billroth-1 (control group). The ulcer located in cardial and mediogastric regions (1 type by Johnson).