Biomaterial Database

Penicillinase plasmid DNA from Staphylococcus aureus. 1969

M G Rush, and C N Gordon, and R P Novick, and R C Warner

A penicillinase plasmid from Staphylococcus aureus and three of its derivatives, all previously identified as extrachromosomal genetic elements, have been isolated in high yield as circular duplex DNA molecules. The wild-type plasmid was found by contour-length measurements of electron micrographs to have a molecular weight of 18.6 x 10(6) daltons. Two plasmids with deletions encompassing six and eight of the eleven known plasmid cistrons had molecular weights of 16.4 x 10(6) and 15.3 x 10(6) daltons, respectively. This information was used to establish approximate physical distances for the genetic map. A high-frequency transducing element also derived from the plasmid had a molecular weight of approximately 24 x 10(6) daltons. Although each plasmid preparation appeared homogeneous by ultracentrifugal analysis, electron micrographs always revealed the presence of a low percentage of complex oligomeric forms, particularly circular and catenated dimers.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008967	Molecular Biology	A discipline concerned with studying biological phenomena in terms of the chemical and physical interactions of molecules.	Biochemical Genetics,Biology, Molecular,Genetics, Biochemical,Genetics, Molecular,Molecular Genetics,Biochemical Genetic,Genetic, Biochemical,Genetic, Molecular,Molecular Genetic
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D004352	Drug Resistance, Microbial	The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).	Antibiotic Resistance,Antibiotic Resistance, Microbial,Antimicrobial Resistance, Drug,Antimicrobial Drug Resistance,Antimicrobial Drug Resistances,Antimicrobial Resistances, Drug,Drug Antimicrobial Resistance,Drug Antimicrobial Resistances,Drug Resistances, Microbial,Resistance, Antibiotic,Resistance, Drug Antimicrobial,Resistances, Drug Antimicrobial
D013210	Staphylococcus	A genus of gram-positive, facultatively anaerobic, coccoid bacteria. Its organisms occur singly, in pairs, and in tetrads and characteristically divide in more than one plane to form irregular clusters. Natural populations of Staphylococcus are found on the skin and mucous membranes of warm-blooded animals. Some species are opportunistic pathogens of humans and animals.
D014161	Transduction, Genetic	The transfer of bacterial DNA by phages from an infected bacterium to another bacterium. This also refers to the transfer of genes into eukaryotic cells by viruses. This naturally occurring process is routinely employed as a GENE TRANSFER TECHNIQUE.	Genetic Transduction,Genetic Transductions,Transductions, Genetic
D014461	Ultracentrifugation	Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D065093	beta-Lactamase Inhibitors	Endogenous substances and drugs that inhibit or block the activity of BETA-LACTAMASES.	beta Lactamase Inhibitor,beta Lactamase Inhibitors,beta-Lactamase Inhibitor,beta Lactamase Antagonists,Antagonists, beta Lactamase,Inhibitor, beta Lactamase,Inhibitor, beta-Lactamase,Inhibitors, beta Lactamase,Inhibitors, beta-Lactamase,Lactamase Antagonists, beta,Lactamase Inhibitor, beta,Lactamase Inhibitors, beta