DNA Restriction and Modification Mechanisms in Bacteria

TL;DR: Evidence is presented that the classification of group II strains is based on restriction modification and is correlated with the presence of a class II restriction enoduclease that recognizes and cleaves the above sequence.

TL;DR: In bacteria, genome-wide mapping of methylated and unmethylated loci is now feasible and sets the stage for comprehensive, mechanistic assessment of the effects of bacterial DNA methyltransferases-which are ubiquitous, extremely diverse, and largely uncharacterized-on gene expression, chromosome structure, chromosome replication, and other fundamental biological processes.

TL;DR: Two species of restriction endonuclease were isolated by gel filtration and DEAE-cellulose chromatography from a cell-free extract of Bacillus amyloliquefaciens (B. subtilits) N strain; a lower molecular weight endonUClease (endonuclease R.BamNI) and a higher molecular-weight one (endonuCx) that required only Mg2+ for their activities.

TL;DR: Findings indicate that DNA methylase II is the modification enzyme corresponding to endonuclease R, and a third modification-restriction system, which does not affect T7 DNA, has been detected in H. influenzae Rd.