Yanli Wang is the Professor and Principal Investigator in Institute of Biophysics, Chinese Academy of Sciences, and a HHMI International Research Scholar. Prof. Wang has completed her PhD from University of Science and Technology of China and postdoctoral studies from Memorial Sloan-Kettering Cancer Center. Prof. Wang's group interests in understanding how small regulatory RNA or DNA mediates prokaryotic defense against invasion by foreign nucleic acids. The main focus of her work is to systematically demonstrate the mechanisms of the CRISPR-Cas system, and Ago protein-mediated DNA interference.

DNA/RNA cleavage by class 2 CRISPR-Cas systems

Class 2 CRISPR-Cas systems are further divided into type II, V and VI. Type II CRISPR-Cas9 protects bacterial hosts against invasive nucleic acids and also provides a revolutionary RNA-guided genome-editing platform. We reported the structural analyses of Cas9 in multiple functional conformations, including pre-catalytic state, catalytically activated state, and post-clavage state. In the catalytic state, the catalytic residues of HNH domain poised closed to the cleavage site of the target DNA, explaining why the HNH domain cleaves target strand between nucleotides 3 and 4.  In type VI, Cas13a exhibits both target and "collateral" cleavage upon target RNA binding. We report a series of structures of Cas13 in complex with crRNA and its complementary target strand. Our studies revealed how Cas13 proteins defend against RNA phages, and the mechanistic insights of Cas13 likely expend the possible application of Cas proteins.