RT Journal Article SR Electronic T1 Biology of DNA restriction. JF Microbiological Reviews JO MICROBIOL. REV. FD American Society for Microbiology SP 434 OP 450 VO 57 IS 2 A1 Bickle, T A A1 Krüger, D H YR 1993 UL http://mmbr.asm.org/content/57/2/434.abstract AB Our understanding of the evolution of DNA restriction and modification systems, the control of the expression of the structural genes for the enzymes, and the importance of DNA restriction in the cellular economy has advanced by leaps and bounds in recent years. This review documents these advances for the three major classes of classical restriction and modification systems, describes the discovery of a new class of restriction systems that specifically cut DNA carrying the modification signature of foreign cells, and deals with the mechanisms developed by phages to avoid the restriction systems of their hosts.