Human DNA ligase I efficiently seals nicks in nucleosomes.
The access to DNA within nucleosomes is greatly restricted for most enzymes and trans-acting factors that bind DNA. We report here that human DNA ligase I, which carries out the final step of Okazaki fragment processing and of many DNA repair pathways, can access DNA that is wrapped about the surface of a nucleosome in vitro and carry out its enzymatic function with high efficiency. In addition, we find that ligase activity is not affected by the binding of linker histone (H1) but is greatly influenced by the disposition of the core histone tail domains. These results suggest that the window of opportunity for human DNA ligase I may extend well beyond the first stages of chromatin reassembly after DNA replication or repair.
Chafin
D R
DR
Department of Biochemistry and Biophysics, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA.
Vitolo
J M
JM
Henricksen
L A
LA
Bambara
R A
RA
Hayes
J J
JJ
D000818:Animals; D004247:DNA / Q000235:genetics* / Q000378:metabolism*; D018983:DNA Footprinting; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004260:DNA Repair / Q000235:genetics*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D017665:Hydroxyl Radical / Q000378:metabolism; D008968:Molecular Conformation; D009154:Mutation; D009707:Nucleosomes / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D014981:Xenopus / Q000235:genetics
D006657:Histones; C000607892:LIG1 protein, human; D009707:Nucleosomes; D017665:Hydroxyl Radical; D004247:DNA; C024408:endodeoxyribonuclease SacI; D015252:Deoxyribonucleases, Type II Site-Specific; D011088:DNA Ligases; D000072481:DNA Ligase ATP