The role of human single-stranded DNA binding protein and its individual subunits in simian virus 40 DNA replication Journal Article
| Authors: | Kenny, M. K.; Schlegel, U.; Furneaux, H.; Hurwitz, J. |
| Article Title: | The role of human single-stranded DNA binding protein and its individual subunits in simian virus 40 DNA replication |
| Abstract: | Human single-stranded DNA binding protein (human SSB) is a multisubunit protein containing polypeptides of 70, 34, and 11 kDa that is required for SV40 DNA replication in vitro. In this report we identify the functions of the SSB and its individual subunits in SV40 DNA replication. The 70 kDa subunit was found to bind to single-stranded DNA, whereas the other subunits did not. Four monoclonal antibodies against human SSB were isolated which inhibited SV40 DNA replication in vitro. The antibodies have been designated αSSB70A, αSSB70B, αSSB70C, and αSSB34A to indicate which subunits are recognized. Immunolocalization experiments indicated that human SSB is a nuclear protein. Human SSB is required for the SV40 large tumor antigen-catalyzed unwinding of SV40 DNA and stimulates DNA polymerases (pol) α and δ. The DNA unwinding reaction and stimulation of polδ were blocked by αSSB70C, whereas the stimulation of polα by human SSB was unaffected by this antibody. Conversely, αSSB70A, -70B, and -34A inhibited the stimulation of polα, but they had no effect on DNA unwinding and polδ stimulation. None of the antibodies inhibited the binding of SSB to single-stranded DNA. These results suggest that DNA unwinding and stimulation of polα and polδ are required functions of human SSB in SV40 DNA replication. The human SSB 70-kDa subunit appears to be required for DNA unwinding and polδ stimulation, whereas both the 70- and 34-kDa subunits may be involved in the stimulation of polα. |
| Keywords: | dna binding protein; human cell; dna-binding proteins; dna replication; cell line; hela cells; antibodies, monoclonal; molecular sequence data; kinetics; dna viruses; simian virus 40; base sequence; dna, viral; single stranded dna; molecular weight; virus dna; dna probes; simiae; oligonucleotide probes; simian virus; human; priority journal; article; support, u.s. gov't, p.h.s.; macromolecular systems |
| Journal Title: | Journal of Biological Chemistry |
| Volume: | 265 |
| Issue: | 13 |
| ISSN: | 0021-9258 |
| Publisher: | American Society for Biochemistry and Molecular Biology |
| Date Published: | 1990-05-05 |
| Start Page: | 7693 |
| End Page: | 7700 |
| Language: | English |
| PUBMED: | 2159011 |
| PROVIDER: | scopus |
| DOI/URL: | |
| Notes: | Source: Scopus |
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