{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T14:31:17Z","timestamp":1781101877057,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"11","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1975,11]]},"abstract":"<jats:p>A method for visualizing RNA-DNA duplex regions along a single strand of DNA in the electron microscope is described. A preparation of RNA molecules is hybridized to a long DNA strand containing the coding sequences (genes) for some of the RNAs. T4 gene 32 protein, which binds selectively and cooperatively only to the single-strand regions, is added, followed by glutaraldehyde. The resulting nucleic acid-gene 32 complex is adsorbed to the surface of an electron microscope grid in the presence of ethidium bromide. The single-strand regions are relatively thick (8.5 nm) compared to the duplex (RNA-DNA hybrid) regions (3.5 nm), so that the two kinds of regions are readily recognized by electron microscopy. In favorable cases, tRNA-DNA hybrids of length about 80 nucleotide pairs can be recognized (although with difficulty). The positions of a number of interesting genetic sequences on the DNA of the transducing phage phi80d3ilvsu+7 have been mapped. The r strand contains 16S, 23S, and 5S rRNA coding sequences in that order. The spacer between 16S and 23S genes has a length of 500 nucleotides and contains the coding sequence for a tRNA2Glu gene in agreement with previous biochemical observations. The spacer between the 23S and 5S genes has a length of 180 nucleotides. The su+7 tRNATrp coding sequence has been mapped on the l strand at a position just to the left of the ilv genes. Secondary structure loops due to short inverted repeat sequences flanking the 16S, 23S, tRNATrp, and F sequences in the DNA have been observed.<\/jats:p>","DOI":"10.1073\/pnas.72.11.4506","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T03:02:33Z","timestamp":1149044553000},"page":"4506-4510","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":43,"title":["Use of gene 32 protein staining of single-strand polynucleotides for gene mapping by electron microscopy: application to the phi80d3ilvsu+7 system."],"prefix":"10.1073","volume":"72","author":[{"given":"M","family":"Wu","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N","family":"Davidson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1975,11]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.72.11.4506","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T10:35:50Z","timestamp":1649846150000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.72.11.4506"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1975,11]]},"references-count":0,"journal-issue":{"issue":"11","published-print":{"date-parts":[[1975,11]]}},"alternative-id":["10.1073\/pnas.72.11.4506"],"URL":"https:\/\/doi.org\/10.1073\/pnas.72.11.4506","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1975,11]]},"assertion":[{"value":"1975-11-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}