Crystal structures of the EVE-HNH endonuclease VcaM4I in the presence and absence of DNA.

Many modification-dependent restriction endonucleases (MDREs) are fusions of a PUA superfamily modification sensor domain and a nuclease catalytic domain. EVE domains belong to the PUA superfamily, and are present in MDREs in combination with HNH nuclease domains. Here, we present a biochemical characterization of the EVE-HNH endonuclease VcaM4I and crystal structures of the protein alone, with EVE domain bound to either 5mC modified dsDNA or to 5mC/5hmC containing ssDNA. The EVE domain is moderately specific for 5mC/5hmC containing DNA according to EMSA experiments. It flips the modified nucleotide, to accommodate it in a hydrophobic pocket of the enzyme, primarily formed by P24, W82 and Y130 residues. In the crystallized conformation, the EVE domain and linker helix between the two domains block DNA binding to the catalytic domain. Removal of the EVE domain and inter-domain linker, but not of the EVE domain alone converts VcaM4I into a non-specific toxic nuclease. The role of the key residues in the EVE and HNH domains of VcaM4I is confirmed by digestion and restriction assays with the enzyme variants that differ from the wild-type by changes to the base binding pocket or to the catalytic residues.

Comparison of the Incidence of Complications and Secondary Surgical Interventions Necessary in Patients with Chronic Lower Limb Ischemia Treated by Both Open and Endovascular Surgeries.

BACKGROUND: Peripheral arterial disease (PAD) affects 3%-10% of the population before the age of 70 years and 15%-20% after that age.The aim of the study was to compare the incidence of complications and secondary interventions in patients who underwent each type of treatment. METHODS: We analyzed 734 medical records of the Department of Surgery at the 4th Military Teaching Hospital in Wroclaw, In total, 394 were operated on with open surgery; an endarterectomy (59.39%), a vascular prosthesis implantation (31.01%), or both of these techniques (6.6%), and 340 patients had angioplasty with (50.59%) or without stenting (49.41%). RESULTS: There were no statistically significant differences in the incidence of corresponding complications. The exception was the infection of the wound; significantly fewer were reported in the case of endovascular procedures (p = 0.0087). There were 12 occasions (3.53%) during endovascular surgeries when intraoperative conversion or re-operation using the open method occurred. In the case of open surgery, the mean hospital stay was 7.77 days (median: 8, mode: 8), while for endovascular management it was equal to 4.68 days (median: 4, mode: 3), p <0.0001. CONCLUSION: The endovascular method results in a similar re-operation rate and number of complications as open surgery.