Fig. 2: Design of a single-domain GFP catenane.

a Cartoon illustration, topology diagram, and gene encoding the original GFP (PDB: 2B3P). Strands are numbered from N-terminal to C-terminal. N and C represent the N-terminal and C-terminal, respectively. b Cartoon illustration, topology diagram, and gene encoding single-domain GFP catenane. The solid bold lines in dark red and dark green represent the newly introduced linkers. Two rings constituting protein catenane are colored in red and green, respectively.