Display Settings:


Send to:

Choose Destination
See comment in PubMed Commons below
Gene. 1991 Jul 31;104(1):75-80.

DNA synthesis on discontinuous templates by DNA polymerase I of Escherichia coli.

Author information

  • 1Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709.


DNA polymerases normally catalyze DNA synthesis in a template-directed manner. Generally, the continuity of the phosphodiester backbone of the template strand was thought to be an absolute requirement for DNA synthesis. Here, I demonstrate that a 3'-exonuclease-deficient derivative of the Klenow (large) fragment of Escherichia coli DNA polymerase I (PolIk) can carry out DNA synthesis on discontinuous templates in vitro. Addition of multiple nucleotides (nt) to the 3' end of a blunt-end duplex, templated by unlinked single-stranded oligodeoxyribonucleotides (oligos), was monitored electrophoretically. The reaction was demonstrable with either homopolymers or mixed-sequence oligos, but showed a requirement for complementarity between the first nt added to the duplex and the 3' nt of the unlinked oligo. These results demonstrate that continuity of the phosphodiester backbone of the template strand is not absolutely required for in vitro DNA synthesis by a 3'-exonuclease-deficient form of PolIk.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk