{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T15:25:58Z","timestamp":1781105158304,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"7","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1973,7]]},"abstract":"<jats:p>\n                    The mechanism of inhibition of human RNA polymerase by four rifamycin derivatives was investigated. Derivative AF\/013 (3-formyl rifamycin SV:\n                    <jats:italic>O-n<\/jats:italic>\n                    -octyloxime) with strong hydrophobic side chains prevents the polymerase from binding to DNA and also affects the size of RNA synthesized. Derivative PR\/19 (3\u2032-acetyl-1\u2032-benzyl-2\u2032-methylpyrrolo[3,2-c]-4-desoxy-rifamycin SV) only affects RNA synthesis when RNA polymerase has been previously incubated with the drug or when the reaction was performed at high salt concentration [0.14 M (NH\n                    <jats:sub>4<\/jats:sub>\n                    )\n                    <jats:sub>2<\/jats:sub>\n                    -SO\n                    <jats:sub>4<\/jats:sub>\n                    ]. Our results suggest that these drugs exert their inhibitory actions by binding to the enzyme instead of DNA.\n                  <\/jats:p>","DOI":"10.1073\/pnas.70.7.2072","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T02:40:11Z","timestamp":1149043211000},"page":"2072-2076","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":16,"title":["Action of Rifamycin Derivatives on RNA Polymerase of Human Leukemic Lymphocytes"],"prefix":"10.1073","volume":"70","author":[{"given":"Ming-Jer","family":"Tsai","sequence":"first","affiliation":[{"name":"Department of Developmental Therapeutics, The University of Texas at Houston, Houston, Texas 77025"},{"name":"M. D. Anderson Hospital and Tumor Institute, Houston, Texas 77025"},{"name":"The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77025"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Grady F.","family":"Saunders","sequence":"additional","affiliation":[{"name":"Department of Developmental Therapeutics, The University of Texas at Houston, Houston, Texas 77025"},{"name":"M. D. Anderson Hospital and Tumor Institute, Houston, Texas 77025"},{"name":"The University of Texas Graduate School of Biomedical Sciences, Houston, Texas 77025"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1973,7]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.70.7.2072","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T10:44:19Z","timestamp":1649846659000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.70.7.2072"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1973,7]]},"references-count":0,"journal-issue":{"issue":"7","published-print":{"date-parts":[[1973,7]]}},"alternative-id":["10.1073\/pnas.70.7.2072"],"URL":"https:\/\/doi.org\/10.1073\/pnas.70.7.2072","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1973,7]]},"assertion":[{"value":"1973-07-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}