title: Expression, purification and biochemical characterization of Methanocaldococcus jannaschii DNA ligase.
abstract: We describe the biochemical characterization of Methanocaldococcus jannaschii (M. jannaschii) DNA ligase and its potential application in single nucleotide polymorphism (SNP) genotyping. The recombinant M. jannaschii DNA ligase is an ATP-dependent ligase. The ligase activity was dependent on metal ions of Mg(2+) and Mn(2+). The optimal concentrations of ATP cofactor and Mg(2+) ion were 0.01-2 and 10 mM, respectively. The optimal pH value for DNA ligation was 8.5. High concentrations of NaCl inhibited DNA ligation. The effects of mismatches on joining short oligonucleotides by M. jannaschii DNA ligase were fully characterized. The mismatches at the first position 5' to the nick inhibited ligation more than those at the first position 3' to the nick. The mismatches at other positions 5' to the nick (3rd to 7th sites) exhibited less inhibition on ligation. However, the introduction of a C/C mismatch at the third position 5' to the nick could completely inhibit the ligation of the terminal-mismatched nick of an oligonucleotide duplex by M. jannaschii DNA ligase. Therefore, introducing an additional mismatch at the third position 5' to the SNP site is a more effective approach in genotyping by M. jannaschii DNA ligase.
authors.affiliation: State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dong-Chuan Road, Shanghai 200240, China.
authors.forename: You
authors.initials: Y
authors.lastname: Wang
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Xie
authors.forename: Zhong
authors.initials: Z
authors.lastname: Han
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Liu
authors.forename: Xi-Peng
authors.initials: XP
authors.lastname: Liu
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D020137:Base Pair Mismatch; D011088:DNA Ligases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D060005:Genotyping Techniques / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D017015:Methanococcales / Q000201:enzymology* / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012965:Sodium Chloride / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D012965:Sodium Chloride; D011088:DNA Ligases