Novel CRISPR Enzymes and Systems

In one aspect, embodiments disclosed herein are directed to engineered CRISPR-Cas effector proteins that comprise at least one modification compared to an unmodified CRISPR-Cas effector protein that enhances binding of the of the CRISPR complex to the binding site and/or alters editing preference as compared to wild type. In certain example embodiments, the CRISPR-Cas effector proteins a Type II effector protein. In certain other example embodiments, the Type V effector protein is Cas9 or an orthologs or engineered variant thereof. Example Cas9 proteins suitable for use in the embodiments disclosed herein are discussed in further detail below.