Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.4 (RNase H)
 2,751 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A RNA-dependent DNA polymerase was isolated from a human cell line derived from the bone marrow of a patient with polycythemia vera. The purification procedure included chromatography on phosphocellulose and oligo(dT)-cellulose, and glycerol gradient centrifugation. The enzyme could be distinguished from polymerase A by salt elution from phosphocellulose, utilization of poly(rC) - oligo(dG) and its molecular size of about 70000, as determined by centrifugation. Throughout the purification procedure ribonuclease H activity was co-purified. Upon dodecylsulfate-polyacrylamide electrophoresis on microgradient gels two main bands with molecular weights of 68000 and 66000 and three minor bands were detected. The enzyme preferentially used poly(rA) - oligo(dT) as template-primer compared with poly(dA) - oligo(dT). It incorporated dGMP into polymer on poly(rC) - oligo(dG).
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PMID:RNA-dependent DNA polymerase from a cell line derived from the bone marrow of a patient with polycythemia vera. 5 57

Reverse transcriptase from the human immunodeficiency virus type I (HIV-1) was expressed in E. coli and purified to near homogeneity. The enzyme was shown to contain reverse transcriptase, DNA polymerase and ribonuclease H activities. The DNA polymerase activity converted singly-primed phi X174 (+) DNA into the double-stranded form. Two third of the replication product is ligatable to covalently closed circular DNA (RFIV-form DNA) indicating that DNA synthesis by HIV reverse transcriptase can proceed until the enzyme matches the 5'-end of a pre-existing primer molecule. The in vitro accuracy of HIV reverse transcriptase was measured with the phi X174am16 reversion assay to be 1/7,400. Reversion rates for the individual mispairs were determined from pool bias studies to be 1/8,000 for the dGMP:T template mismatch, 1/35,000 for the dGMP:A template mismatch, 1/45,000 for the dAMP:G template mismatch, 1/73,000 for the dCMP:T template mispair, 1/140,000 for the dCMP:A template mispair, and 1/180,000 for the dGMP:G template mismatch. The dTMP:T template mispair was below the detection limit of the assay indicating a reversion rate of less than 1/300,000 for this particular mispair.
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PMID:Fidelity of human immunodeficiency virus type I reverse transcriptase in copying natural DNA. 246 38