这个词是什么意思？
Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.
中文名称索引；定义为 MeSH 英文原文，尚未逐条译审。MESH:D004262 · MeSH 2026。
Courtesy of the U.S. National Library of Medicine. Annual snapshot; later updates may not be reflected. NLM does not endorse this service.