CRISPR-Cas Systems in Streptococci
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Updated: Jan 23, 2026

Substrate Generation for Endonucleases of CRISPR/Cas Systems
Published on: September 8, 2012
Tao Gong1, Miao Lu1, Xuedong Zhou1
1State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.
Abstract:
Streptococci are one of the most important and common constituents of the host's microbiota and can colonize and live in the upper respiratory and urogenital tract of humans and animals. The CRISPR-Cas systems (i.e., clustered regularly interspaced short palindromic repeat, with CRISPR-associated proteins) found in bacteria and archaea provide sequence-based adaptive immunity against mobile genetic elements, especially in the streptococci. Here, recent research progress on CRISPR-Cas systems in the streptococci is reviewed, including their classification (mainly type I, type II, and type III), physiological function, defense mechanism (CRISPR adaptation, crRNA biogenesis, and target interference) and applications, which are useful for a better understanding of the functions of such systems. Finally, the advances that have been made in streptococci may help in the discovery of further novel CRISPR-Cas systems for use in new technologies and applications in other species.
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