Engineered split in Pfu DNA polymerase fingers domain improves incorporation of nucleotide gamma-phosphate derivative

Nucleic Acids Res. 2011 Mar;39(5):1801-10. doi: 10.1093/nar/gkq1053. Epub 2010 Nov 9.

Abstract

Using compartmentalized self-replication (CSR), we evolved a version of Pyrococcus furiosus (Pfu) DNA polymerase that tolerates modification of the γ-phosphate of an incoming nucleotide. A Q484R mutation in α-helix P of the fingers domain, coupled with an unintended translational termination-reinitiation (split) near the finger tip, dramatically improve incorporation of a bulky γ-phosphate-O-linker-dabcyl substituent. Whether synthesized by coupled translation from a bicistronic (-1 frameshift) clone, or reconstituted from separately expressed and purified fragments, split Pfu mutant behaves identically to wild-type DNA polymerase with respect to chromatographic behavior, steady-state kinetic parameters (for dCTP), and PCR performance. Although naturally-occurring splits have been identified previously in the finger tip region of T4 gp43 variants, this is the first time a split (in combination with a point mutation) has been shown to broaden substrate utilization. Moreover, this latest example of a split hyperthermophilic archaeal DNA polymerase further illustrates the modular nature of the Family B DNA polymerase structure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Archaeal Proteins / chemistry*
  • Archaeal Proteins / genetics
  • Archaeal Proteins / metabolism
  • DNA-Directed DNA Polymerase / chemistry*
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism
  • Directed Molecular Evolution
  • Molecular Sequence Data
  • Nucleotides / chemistry
  • Nucleotides / metabolism
  • Phosphates / chemistry
  • Protein Engineering
  • Protein Structure, Tertiary
  • Sequence Alignment

Substances

  • Archaeal Proteins
  • Nucleotides
  • Phosphates
  • Pfu DNA polymerase
  • DNA-Directed DNA Polymerase