Mispairs with Watson-Crick base-pair geometry observed in ternary complexes of an RB69 DNA polymerase variant.
Recent structures of DNA polymerase complexes with dGMPCPP/dT and dCTP/dA mispairs at the insertion site have shown that they adopt Watson-Crick geometry in the presence of Mn(2+) indicating that the tautomeric or ionization state of the base has changed. To see whether the tautomeric or ionization state of base-pair could be affected by its microenvironment, we determined 10 structures of an RB69 DNA polymerase quadruple mutant with dG/dT or dT/dG mispairs at position n-1 to n-5 of the Primer/Template duplex. Different shapes of the mispairs, including Watson-Crick geometry, have been observed, strongly suggesting that the local environment of base-pairs plays an important role in their tautomeric or ionization states.
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, 06520-8114.
Shuangluo
S
Xia
William H
WH
Konigsberg
D020137:Base Pair Mismatch; D020029:Base Pairing; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D014644:Genetic Variation / Q000235:genetics*; D008958:Models, Molecular; D008968:Molecular Conformation; D009154:Mutation; D015202:Protein Engineering; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
D014764:Viral Proteins; D004259:DNA-Directed DNA Polymerase; C463461:bacteriophage RB69 DNA polymerase
RB69 DNA polymerase; Watson-Crick base-pairs; tautomerization; thymine-guanine mispairs