讲座时间：14:00 — 15:30
题目：CRISPR-Cas Mediated Cleavage of Invading Nucleic Acids
Bacteria and archaea are protected against invading nucleic acids from phages and plasmids because of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas (CRISPR associated proteins) systems, which are RNA-guided prokaryotic adaptive immune system. CRISPR-Cas systems are found in nearly half of all bacteria studied so far, as well as in the majority of archaea. However, throughout evolution, this host defense system has not resulted in the eradication of phages, suggesting that phages have evolved counter strategies to thrive within bacteria despite these mechanisms. Thus, both bacterial CRISPR system and phage anti-CRISPR system are part of a continuing evolutionary battle between bacterial host and their bacteriophage invaders. We provided significant insights into the molecular mechanism for how CRISPR-Cas systems defend against the invading nucleic acids from phages and how phages counteract the CRISPR-Cas systems by anti-CRIPR proteins.