title: Formation of single-stranded DNA during DNA transformation of Neisseria gonorrhoeae.
abstract: Neisseria gonorrhoeae is naturally competent for DNA transformation. In contrast to other natural prokaryotic DNA transformation systems, single-stranded donor DNA (ssDNA) has not previously been detected during transformation of N. gonorrhoeae. We have reassessed the physical nature of gonococcal transforming DNA by using a sensitive nondenaturing native blotting technique that detects ssDNA. Consistent with previous analyses, we found that the majority of donor DNA remained in the double-stranded form, and only plasmid DNAs that carried the genus-specific DNA uptake sequence were sequestered in a DNase I-resistant state. However, when the DNA was examined under native conditions, S1 nuclease-sensitive ssDNA was identified in all strains tested except for those bacteria that carried the dud-1 mutation. Surprisingly, ssDNA was also found during transformation of N. gonorrhoeae comA mutants, which suggested that ssDNA was initially formed within the periplasm.
authors.affiliation: Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA mchaussee@nih.gov
authors.forename: M S
authors.initials: MS
authors.lastname: Chaussee
authors.forename: S A
authors.initials: SA
authors.lastname: Hill
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D015139:Blotting, Southern / Q000379:methods; D004269:DNA, Bacterial / Q000096:biosynthesis* / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000096:biosynthesis* / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D009154:Mutation; D009344:Neisseria gonorrhoeae / Q000235:genetics* / Q000378:metabolism; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000235:genetics; D012680:Sensitivity and Specificity; D014169:Transformation, Bacterial / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; C061262:ComA protein, Bacteria; D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins