Plasmid Mor174 has a molecular weight of 3.6 X 10(6) and a buoyant density of 1.6994 g/cm3. The covalently closed circular form has a sedimentation coefficient of 22S. These are 30 to 40 plasmid copies per genome equivalent, but growth in chloramphenicol results in amplification of the copy number to 600. In Proteus morganii 174, Mor174 coexists with a cryptic plasmid of molecular weight 15.8 X...

A computer program is described which creates circular and linear genetic maps with or without sequences, performs restriction analysis, and simulates basic molecular cloning operations. Redasoft Plasmid 1.1 is a user-friendly program for Windows 95/98/NT/2000, designed to generate high quality genetic maps for presentation and publication and to aid the molecular biologist in selecting restric...

Gene knockout, an important technology in molecular biology, has been broadly applied in industrial microbial metabolic engineering. From the basic mechanism of DNA recombination, we summarized and compared in this review different gene knockout strategies. Three most hot and important approaches, including the lambda Red recombination system using the linear dsDNA as recombination substrate, t...

UNLABELLED 1,2-Dichloroethane (DCA) is a problematic xenobiotic groundwater pollutant. Bacteria are capable of biodegrading DCA, but the evolution of such bacteria is not well understood. In particular, the mechanisms by which bacteria acquire the key dehalogenase genes dhlA and dhlB have not been well defined. In this study, the genomic context of dhlA and dhlB was determined in three aerobic ...

Mimosine, DNA breaKs, Free Radicals, Fenton Reaction Supercoiled plasmid DNA was treated in vitro with H2O2, DTT and either Fe (II), Fe (II)-EDTA or Fe (II)-mimosine. The rate of DNA break formation was followed by the conversion of the supercoiled form into relaxed-circular and linear forms. In the concentration interval of 0-4 microM Fe (II), Fe (II)-EDTA slowed-down the formation of DNA brea...

BACKGROUND With the rapid development of synthetic biology, the demand for assembling multiple DNA (genes) fragments into a large circular DNA structure in one step has dramatically increased. However, for constructions of most circular DNA, there are two contradictions in the ligation/assembly and transformation steps. The ligation/assembly consists of two different reactions: 1) the ligation/...

The binding of core histones (H2A, H2B, H3, H4) to a circular plasmid DNA and to a circular DNA-RNA hybrid molecule of similar size has been compared. Circular hybrid molecules were formed from single stranded fd DNA by synthesis of the complimentary strand with ribonucleotides using wheat germ RNA polymerase II. Upon reconstitution of plasmid DNA circles with histone, the sedimentation profile...

Linear chromosomes and linear plasmids of Streptomyces possess covalently bound terminal proteins (TPs) at the 5' ends of their telomeres. These TPs are proposed to act as primers for DNA synthesis that patches the single-stranded gaps at the 3' ends during replication. Most ('archetypal') Streptomyces TPs (designated Tpg) are highly conserved in size and sequence. In addition, there are a numb...

Staphylococcal phage group 2 strain UT0007 was previously shown to contain a high-molecular-weight plasmid containing genes for exfoliative toxin (ET) and bacteriocin production. Phage group 2 strains UT0002 and UT0003 (Tox+Bac-) underwent a twofold and ninefold loss of ET activity, respectively, after growth at 44 C for 18 h. Strain UT0002 also lost total bacteriocin activity. Both strains con...