Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Topoisomerase cDNA and various fragments thereof generated by the DNA polymerase chain reaction were cloned into plasmid expression vectors (pET series) and the expressed polypeptides were probed with scleroderma sera from seven different patients immunoreactive with topoisomerase I. All sera reacted selectively with a region between amino acid residues 405 and 484 of human topoisomerase I. This conclusion is based on loss of reactivity when this region was omitted from larger pieces. Other portions of topoisomerase I were not reactive with these autoantibodies. At least two different epitopes appear to be recognized within this region by different sera based on differences in immunoreactivity of the 405-484 region when expressed as C-terminal, N-terminal or internally within a peptide.
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PMID:An antigenic region of topoisomerase I in DNA polymerase chain reaction-generated fragments recognized by autoantibodies of scleroderma patients. 171 70

Sera from patients suffering from autoimmune diseases were analyzed for the presence of antibodies that inhibit adenovirus DNA replication in vitro. DNA replication was studied in a reconstituted system containing purified viral proteins (DNA binding protein, DNA polymerase and the precursor to the terminal protein) and a crude nuclear extract from HeLa cells. About half the autoimmune sera analyzed inhibited DNA replication by more than 50% while only 2 out of 31 control sera showed strong inhibition. The inhibition was caused by the IgG fractions of the sera and was most frequently observed with sera from scleroderma patients. Several lines of evidence indicate that the inhibition is not due to anti-DNA antibodies. The mechanism of inhibition of two strongly inhibitory sera was further investigated. The IgG fractions from these sera blocked DNA chain elongation more than 80% but had no effect on the initiation step or the synthesis of the first 26 nucleotides. Using a dot blot assay and different incubation conditions, evidence was obtained that the inhibition is due to immunorecognition of a nuclear factor from HeLa cells. Two nuclear proteins are known to be required for adenovirus DNA replication, nuclear factors I and II. DNA replication in the presence of purified nuclear factor I instead of a crude nuclear extract was only slightly inhibited by the antisera. In agreement with this, immunorecognition of nuclear factor I could not be detected using a dot blot assay. Since nuclear factor II is not required in our assay system, these results suggest the existence of another nuclear component involved in adenovirus DNA replication which is neutralized by these antibodies.
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PMID:Inhibition of adenovirus DNA replication in vitro by autoimmune sera. 394 34