The repair patch of E. coli (A)BC excinuclease.
The size of repair patch made by E. coli DNA polymerase I (Poll) following the removal of a thymine-psoralen monoadduct by E. coli (A)BC excinuclease was determined by using an M13mp19 DNA with a single psoralen monoadduct at the polylinker region. Incubation of this substrate with (A)BC excinuclease, Poll and a combination of 3 dnTP plus 1 dNTP(alpha S) for each nucleotide, and DNA ligase resulted in a repair patch with phosphorothioate linkages. The preferential hydrolysis of phosphorothioate bonds by heating in iodoethanol revealed a patch size--with minimal nick translation--equal in length to the 12 nucleotide gap generated by this excision nuclease.
Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill 27599.
Sibghat-Ullah
A
A
Sancar
J E
JE
Hearst
D001483:Base Sequence; D004260:DNA Repair; D004269:DNA, Bacterial / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D005363:Ficusin / Q000494:pharmacology; D008969:Molecular Sequence Data; D013936:Thymidine / Q000378:metabolism
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D004706:Endodeoxyribonucleases; C036385:endodeoxyribonuclease uvrABC; D005363:Ficusin; D013936:Thymidine