title: [T4-DNA ligase: substrate properties of synthetic DNA-duplexes with structural anomalies].
abstract: Structural defects, affecting T4 DNA ligase function, were revealed with the help of synthetic DNA duplexes, containing modifications at single nick. Changes of configuration at C2' and C3' atoms of furanose in the acceptor terminus lead to total blocking of the nick sealing activity of T4 DNA ligase. On the contrary, substitution of 3'-terminal deoxyribonucleotide for ribonucleotide doesn't affect the enzyme's action. The duplex looses all of it's substrate activity if the next from the nick G.C pair is substituted for the noncomplementary G.C pair. In DNA duplexes containing an unpaired base in the nick, elimination of the extrahelical nucleotide proceeds the ligation step. In these cases the duplex substrate activity decreases depending on the extent of extrahelical base stacking into the double stranded DNA.
authors.forename: A V
authors.initials: AV
authors.lastname: Tsytovich
authors.forename: N G
authors.initials: NG
authors.lastname: Dolinnaia
authors.forename: Z A
authors.initials: ZA
authors.lastname: Shabarova
mesh_terms: D002384:Catalysis; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D009692:Nucleic Acid Heteroduplexes / Q000378:metabolism*; D011118:Polynucleotide Ligases / Q000378:metabolism*; D013379:Substrate Specificity; D013604:T-Phages / Q000201:enzymology*
chemical_list: D004279:DNA, Viral; D009692:Nucleic Acid Heteroduplexes; D011088:DNA Ligases; D011118:Polynucleotide Ligases; D000072481:DNA Ligase ATP
vernacular_title: T4-DNK-ligaza: substratnye svoĭstva sinteticheskikh DNK-dupleksov so strukturnymi anomaliiami.