title: A new hybrid plasmid capable of transforming Escherichia coli and Anacystis nidulans.
abstract: We have constructed a hybrid plasmid, pDF30, by combining the 8-kb pDF3 plasmid derived from the cyanobacterium Anacystis nidulans 6311 with the Escherichia coli vector pBR325. pDF30 transforms, replicates and confers chloramphenicol resistance (Cmr) and ampicillin resistance (Apr) on both A. nidulans and E. coli. The level of resistance to ampicillin in A. nidulans transformants, although low, is above background resistance and an Apr activity was demonstrated in cell-free extracts of A. nidulans that harbored pDF30. pDF30 is stably maintained within E. coli and can be isolated intact from A. nidulans after several months of subculture under chloramphenicol selection and by this criterion is stable in vivo. The unique restriction sites for XhoI, SalI and EcoRI can be used for molecular cloning of chromosomal genes in E. coli and A. nidulans. Until now pDF3 is phenotypically cryptic in both A. nidulans and E. coli. Examination of the polypeptides encoded on and expressed by pDF30 in E. coli minicells revealed only gene products from pBR325 but none from pDF3.
mesh_terms: D001483:Base Sequence; D000458:Cyanobacteria / Q000235:genetics*; D004262:DNA Restriction Enzymes; D004274:DNA, Recombinant / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D014176:Protein Biosynthesis; D014169:Transformation, Bacterial; D014170:Transformation, Genetic
chemical_list: D004274:DNA, Recombinant; D004262:DNA Restriction Enzymes