Engineered cas-phi proteins and uses thereof

A composition comprising an engineered polypeptide or a nucleic acid encoding the engineered polypeptide, wherein the engineered polypeptide comprises one or more amino acid substitutions relative to SEQ ID NO:

• 1, wherein the one or more amino acid substitutions are selected from:
• I2R, T5R, K15R, R18R, H20R S21R, L26R, L26K, N30R, E33R, E34R, A35R, K37R, K38R, R41R, N43R, Q54R Q79R, K92E, K99R, S108R, E109R, H110R, G111R, D113R, T114R, P116R, K118R, E119S, A121Q, N132R, K135R, Q138R V139R, L149R, Y180R, L182R, Q183R, K184R, S186R, K189R, K189P, S196R, S198R, K200R, 1203R S205R, K206R, Y207R, H208R, N209R, Y220S, S223P, E258K, K281R, K348R, N355R, N406K, K4350, 1471T, V521T, N568D, S579R, Q612R, S638K, F701R, and P707R, and a combination thereof;
• and wherein other than the one or more amino acid substitutions, the engineered polypeptide comprises an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO:
• 1.