Herein, we present a simple linear motor, built from DNA and a restriction enzyme, which moves a DNA cargo in discrete steps along a DNA track. Movement is powered by a nicking enzyme that cuts the track. Damage to the track in the wake of the cargo imposes directionality. The specificity of base-pairing, the rigidity of short segments of the double helix, and the flexibility of singlestranded ...

A frequently passaged laboratory strain of Campylobacter jejuni was confirmed by serotyping on the basis of thermostable antigens and by bacterial chromosomal restriction endonuclease digests to be the causative agent of enteritis in a laboratory worker.

A convenient 'DNA shuffling' protocol for random recombination of homologous genes in vitro with a very low rate of associated point mutagenesis (0.05%) is described. In addition, the mutagenesis rate can be controlled over a wide range by the inclusion of Mn2+or Mg2+during DNase I digestion, by choice of DNA polymerase used during gene reassembly as well as how the genes are prepared for shuff...

lambda-exonuclease participates in DNA recombination and repair. It binds a free end of double-stranded DNA and degrades one strand in the 5' to 3' direction. The primary sequence does not appear to be related to any other protein, but the crystal structure shows part of lambda-exonuclease to be similar to the type II restriction endonucleases PvuII and EcoRV. There is also a weaker corresponde...

Type II restriction endonucleases Bam HI and Eco RI were covalently coupled to Sepharose. These insolubilized enzymes generated fragment patterns for several viral DNAs identical to those produced by the respective free enzymes. Conditions for optimal activity were similar for both bound and unbound forms of the enzymes. Insolubilization improved thermal stability of Bam HI and Eco RI. The boun...

The type II restriction endonuclease TseI recognizes the DNA target sequence 5'-G^CWGC-3' (where W = A or T) and cleaves after the first G to produce fragments with three-base 5'-overhangs. We have determined that it is a dimeric protein capable of cleaving not only its target sequence but also one containing A:A or T:T mismatches at the central base pair in the target sequence. The cleavage of...

Conventional alkaline C-banding was found to be an effective additional step in restriction endonuclease banding to improve staining contrast and to reveal hidden changes in the heterochromatic blocks. Examples of these cases are demonstrated on the bovine chromosome set using Hinf I and Taq I endonucleases in the digestion experiments.

An extra variant G band in a human 9qh+ region was analysed in normally condensed and 5-azacytidine undercondensed chromosomes. Fluorescence in situ hybridisation showed that specific, classical, alphoid and beta satellite DNA was not present. Nevertheless, this extra band behaves like the surrounding heterochromatin because (1) its chromatin fibres showed condensation inhibition after 5-azacyt...

“Jumbo phages” are an emergent and ubiquitous class of large (>200 kb) dsDNA bacteriophages—viruses that infect bacteria—that construct a selectively-permeable, proteinaceous compartment around their replicating genome during infection. This micron-scale compartment, termed the “phage nucleus”, forms de novo grows with viral DNA. The phage nucleus allows export mRNA import select DNA replicatio...

The product of the induced relaxation of supercoiled DNA-protein relaxation complexes of colicinogenic factors E1 (ColE1) and E2 (ColE2) is an open circular DNA molecule with a strand-specific nick. Cleavage of the open circular DNA of each relaxed complex with the EcoRI restriction endonuclease demonstrates that the single-strand break is at a unique position. The site of the single-strand bre...