Abstract
A 120-kDa protein that blocks DNA termini has been purified from extracts of HeLa cells. This protein inhibits the action of a number of enzymes that catalyze reactions involving the 5' and 3' ends of DNA (DNA ligase, 3' and 5' exonucleases, and DNA polymerase alpha). The 120-kDa protein blocks the synthesis of long DNA chains that are normally formed during simian virus 40 DNA replication, causing the accumulation of small DNA fragments. The effects of this protein can be reversed by the addition of proliferating cell nuclear antigen and other protein fractions (activators).
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Antigens, Neoplasm
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DNA Ligases / metabolism
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DNA Polymerase II / metabolism
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DNA Replication*
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DNA, Viral / antagonists & inhibitors*
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DNA, Viral / biosynthesis
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DNA-Binding Proteins / isolation & purification*
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DNA-Binding Proteins / metabolism
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Exodeoxyribonuclease V
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Exodeoxyribonucleases / metabolism
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HeLa Cells / metabolism
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Humans
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Kinetics
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Molecular Weight
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Nuclear Proteins / physiology*
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Proliferating Cell Nuclear Antigen
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Simian virus 40 / metabolism*
Substances
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Antigens, Neoplasm
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DNA, Viral
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DNA-Binding Proteins
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Nuclear Proteins
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Proliferating Cell Nuclear Antigen
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DNA Polymerase II
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Exodeoxyribonucleases
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Exodeoxyribonuclease V
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DNA Ligases