Sort-seq assays of single fluorescent protein biosensor libraries

Libraries of single fluorescent protein biosensor variants were constructed with variation in either the site of GFP insertion into a ligand-binding domain or the composition of amino acid linkers connecting domains. The pooled libraries were characterized by a massively parallel assay combining FACS and DNA sequencing. A maltose-binding protein domain-insertion library was screened in E. coli. A library of linker mutations to the pyruvate biosensor PyronicSF was screened in HEK 293T TetBxb1BFP "landing pad" cell line.