Sibghat-Ullah,Sancar, A1992-06-012009-05-271992-06-012009-05-271992-06-01Sibghat-Ullah , Sancar A. In vitro characterization of repair synthesis initiated by T4 endonuclease V on a synthetic DNA substrate. Indian Journal of Biochemistry & Biophysics. 1992 Jun; 29(3): 227-30http://imsear.searo.who.int/handle/123456789/27303The size of the repair patch produced by E. coli DNA polymerase (Pol I) following the removal of a pyrimidine dimer from DNA in response to the nicking activity of T4 endonuclease (T4 endo V) was determined. A 48-bp DNA containing a pyrimidine dimer at a defined location was labelled in the damaged strand and incubated with T4 endo V and E. coli endonuclease IV. Subsequently, DNA synthesis by DNA Pol I was carried out in the presence of four dNTPs, ATP and DNA ligase. Analysis of the reaction products on a sequencing gel revealed a ladder of only 4-oligonucleotides, 1-4 nucleotides greater in length than the fragment generated by the combined nicking activities of T4 endo V and E. coli endonuclease IV. Thus we conclude that the in vitro repair patch size of T4 endo V is 4 nucleotides and that in some cases the repaired DNA is not ligated.engBase SequenceDNA --metabolismDNA Polymerase I --metabolismDNA RepairDNA ReplicationDeoxyribonuclease (Pyrimidine Dimer)Endodeoxyribonucleases --metabolismEscherichia coli --enzymologyModels, StructuralMolecular Sequence DataNucleic Acid ConformationOligodeoxyribonucleotidesSubstrate SpecificityT-Phages --enzymologyViral ProteinsJournal Article