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Updated: Aug 30, 2026

In Vitro Directed Evolution of a Restriction Endonuclease with More Stringent Specificity
Published on: March 25, 2020
Maintenance of species identity and controlling speciation of bacteria: a new function for restriction/modification
1Institut für Biochemie, FB 08, Justus-Liebig-Universität, Heinrich-Buff-Ring 58, 35392 Giessen, Germany. Albert.Jeltsch@chemie.bio.uni-giessen.de
Abstract:
Bacteria frequently exchange DNA among each other by horizontal gene transfer. However, maintenance of species identity and in particular speciation requires a certain barrier against an unregulated uptake of foreign DNA. Here it is suggested that formation of such a barrier is one important biological function of restriction/modification systems, in addition to the classical function of protection of bacteria against bacteriophage infection. This model explains the extreme variability and wide distribution of restriction/modification systems among prokaryotes, the prevalence of RM-systems in pathogenic bacteria and the existence of several RM-systems in single bacterial strains.
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