The relative binding affinities of Mnt protein from bacteriophage P22 are determined for each possible base pair at position 17 of the operator. These are determined from the partitioning of randomized operators into bound and unbound fractions; quantitation is provided by restriction enzyme analysis. Mnt protein is found to have an unusual specificity at this position: a C.G base pair (the wil...

  Objective(s): Fascioliasis is a zoonotic parasitic disease caused by liver fluke species of Fasciola hepatica and Fasciola gigantica. Differentiation of these two species, based on their morphological characteristics, is difficult. The current study aimed to use PCR-RFLP assay to distinguish between F. hepatica and F. gigantica , based on profiles of RFLP, produced by effect of endo...

We present a method for cloning restriction-modification (R-M) systems that is based on the use of a lethal plasmid (pKILLER). The plasmid carries a functional gene for a restriction endonuclease having the same DNA specificity as the R-M system of interest. The first step is the standard preparation of a representative, plasmid-borne genomic library. Then this library is transformed with the k...

Two plasmid-carried restriction-modification (R-M) systems, EcoRI (from pMB1 of Escherichia coli) and Bsp6I (from pXH13 of Bacillus sp. strain RFL6), enhance plasmid segregational stability in E. coli and Bacillus subtilis, respectively. Inactivation of the endonuclease or the presence of the methylase in trans abolish the stabilizing activity of the R-M systems. We propose that R-M systems med...