Compositions for linking zinc finger modules

A zinc finger protein comprising a plurality of non-naturally occurring zinc finger modules, wherein at least two of the non-naturally occurring zinc finger DNA-binding modules are joined by an amino acid linker sequence of 5 to 20 amino acid residues between the last residue of the N-terminal zinc finger module and the first residue of C-terminal zinc finger module, the amino acid linker comprising an N-terminal amino acid residue adjacent to the N-terminal zinc finger module, a C-terminal amino acid residue adjacent to the C-terminal zinc finger module, and amino acid residues internal to the N- and C-terminal amino acid linker residues, wherein

• (i) the N-terminal amino acid linker residue or the internal amino acid linker residues comprises at least one proline residue;
• (ii) the zinc finger protein binds to a target site comprising target subsites bound by each zinc finger module;
• and
• (iii) there is a gap of 0, 1, 2 or 3 base pairs between the target subsites bound by the zinc finger DNA-binding modules joined by the amino acid linker.