Customizing CRISPR-Cas PAM specificity with protein language models
We developed Protein2PAM, an evolution-informed protein language model that predicts PAM specificity of CRISPR-Cas proteins. Using in silico mutagenesis and model-guided evolution, we generated Cas9 variants with broadened PAM compatibility and increased activity, enabling editing of genomic sites that were previously inaccessibile due to PAM constraints.