title: Transfection of Escherichia coli and Salmonella typhimurium spheroplasts: host-controlled restriction of infective bacteriophage P22 deoxyribonucleic acid.
abstract: Under proper conditions, one infective center was obtained for 3 x 10(8) molecules of P22 phage deoxyribonucleic acid (DNA) when lysozyme-ethylenediaminetetraacetic acid spheroplasts of Escherichia coli were transfected in the presence of 25 mug of protamine sulfate per ml. A 3- to 50-fold B-specific and K-specific E. coli restriction of the incoming P22 DNA was observed. When P22 DNA-infected E. coli spheroplasts were plated with infertile r(LT) (+)m(LT) (+)Salmonella typhimurium indicator, an additional 70-fold restriction was observed. In the presence of protamine sulfate, penicillin spheroplasts of S. typhimurium SB1330 could be transfected b P22 DNA with efficiencies sometimes approaching those obtained with the E. coli spheroplasts; thus, facilitation of transfection by protamine sulfate is not limited to E. coli or to lysozyme-ethylenediaminetetraacetic acid spheroplasts. The application of these results to studies of transfection among other genuses and to studies of in vitro host-controlled restriction and modification for the two loci in S. typhimurium and the one locus in E. coli is discussed.
mesh_terms: D002499:Centrifugation, Density Gradient; D002586:Cesium; D011232:Chemical Precipitation; D002712:Chlorides; D004279:DNA, Viral / Q000302:isolation & purification; D004492:Edetic Acid; D004926:Escherichia coli; D009113:Muramidase; D010405:Penicillinase; D010406:Penicillins; D011479:Protamines / Q000494:pharmacology; D011523:Protoplasts; D012483:Salmonella Phages / Q000302:isolation & purification; D012486:Salmonella typhimurium; D013431:Sulfates / Q000494:pharmacology; D014170:Transformation, Genetic / Q000187:drug effects
chemical_list: D002712:Chlorides; D004279:DNA, Viral; D010406:Penicillins; D011479:Protamines; D013431:Sulfates; D002586:Cesium; D004492:Edetic Acid; D009113:Muramidase; D010405:Penicillinase