Engineered mcp and pcp proteins and systems and methods thereof

An engineered MS2 coat protein (MCP;

• cpmMCP) comprising an engineered RNA-binding domain;
• wherein the engineered MCP protein is stable when the engineered RNA-binding domain is bound to an MS2 RNA hairpin loop;
• wherein when the engineered RNA-binding domain is not bound to the MS2 RNA hairpin loop, the engineered MCP protein is unstable and degradation of the engineered MCP protein increases.

An engineered PP7 coat protein (PCP) comprising an engineered RNA-binding domain and a degron;

• wherein the degron is hidden upon binding of the engineered RNA-binding domain to a PP7 RNA hairpin loop;
• wherein when the engineered RNA-binding domain is not bound to the PP7 RNA hairpin loop, the degron is exposed and degradation of the engineered PCP protein increases.

An engineered PP7 coat protein (PCP) comprising an engineered RNA-binding domain;

• wherein the engineered PCP protein is stable when the engineered RNA-binding domain is bound to a PP7 RNA hairpin loop;
• wherein when the engineered RNA-binding domain is not bound to the PP7 RNA hairpin loop, the engineered PCP protein is unstable and degradation of the engineered PCP protein increases.