DNA end processing by polynucleotide kinase/phosphatase
نویسندگان
چکیده
منابع مشابه
DNA end processing by polynucleotide kinase/phosphatase.
S cission of one or both strands of the DNA duplex occurs as ionizing radiation and oxidative DNA damage mount a constant assault our genomes. Like a broken limb, or split piece of wood, DNA strand breaks are typically not clean. That is, they lack the DNA 3′-hydroxyl and 5′-phosphate moieties needed for DNA repair synthesis by DNA polymerases and DNA end joining by DNA ligases (Fig. 1A). For i...
متن کاملXrcc4 physically links DNA end processing by polynucleotide kinase to DNA ligation by DNA ligase IV.
Nonhomologous end joining (NHEJ) is the major DNA double-strand break (DSB) repair pathway in mammalian cells. A critical step in this process is DNA ligation, involving the Xrcc4-DNA ligase IV complex. DNA end processing is often a prerequisite for ligation, but the coordination of these events is poorly understood. We show that polynucleotide kinase (PNK), with its ability to process ionizing...
متن کاملDouble-Strand Breaks by Nonhomologous End Joining but Human Polynucleotide Kinase Participates in Repair of DNA
Human polynucleotide kinase (hPNK) is a bifunctional enzyme possessing a 5¶-DNA kinase activity and a 3¶-phosphatase activity. Studies based on cell extracts and purified proteins have indicated that hPNK can act on single-strand breaks and double-strand breaks (DSB) to restore the termini to the chemical form required for further action by DNA repair polymerases and ligases (i.e., 5¶-phosphate...
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DNA strand-breaks (SBs) with non-ligatable ends are generated by ionizing radiation, oxidative stress, various chemotherapeutic agents, and also as base excision repair (BER) intermediates. Several neurological diseases have already been identified as being due to a deficiency in DNA end-processing activities. Two common dirty ends, 3'-P and 5'-OH, are processed by mammalian polynucleotide kina...
متن کاملRecognition of DNA substrates by T4 bacteriophage polynucleotide kinase.
T4 phage polynucleotide kinase (PNK) displays 5'-hydroxyl kinase, 3'-phosphatase and 2',3'-cyclic phosphodiesterase activities. The enzyme phosphorylates the 5' hydroxyl termini of a wide variety of nucleic acid substrates, a behavior studied here through the determination of a series of crystal structures with single-stranded (ss)DNA oligonucleotide substrates of various lengths and sequences....
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 2011
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.1118214109