title: [DNA-duplexes with phosphoamide bond: interaction with restriction endonucleases EcoRII and SsoII].
abstract: We studied the interaction of EcoRII and SsoII restriction endonucleases with synthetic DNA duplexes, containing 3'N----5'P and 3'P----5'N phosphoamide internucleotide bonds in one of the cleavage points. Enzymatic hydrolysis of the modified strand of the duplexes is blocked in all cases. The presence of phosphoamide bonds was found to reduce the rate of cleavage of the natural strand by EcoRII and to have no influence in case of SsoII. Properties of the EcoRII endonuclease complex with its substrate, containing non-cleavable 3'N----5'P internucleotide bonds in each cleavage point, were examined. In the presence of Mg2+ ions the equilibrium association constant of the enzyme-substrate complex is 3-fold reduced, and the dissociation rate constant of the complex is increased by 1.5 times.
mesh_terms: D001483:Base Sequence; D004247:DNA; D004262:DNA Restriction Enzymes; D015252:Deoxyribonucleases, Type II Site-Specific; D006868:Hydrolysis; D013379:Substrate Specificity
chemical_list: D004247:DNA; D004262:DNA Restriction Enzymes; C045297:CCNGG-specific type II deoxyribonucleases; C046545:CCWGG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific
vernacular_title: DNK-dupleksy s fosfoamidnoĭ sviaz'iu: vzaimodeĭstvie s éndonukleazarestriktsii EcoRII i SsoII.