Patent ID: 8003346

Claim:
A mutant proliferating cell nuclear antigen (PCNA) monomer comprising an amino acid sequence obtained by substituting at least: (A) a first amino acid residue at a position selected from positions 82, 84, and 109 in SEQ ID NO:2 or SEQ ID NO: 32 and (B) a second amino acid residue at a position selected from positions 139, 143, and 147 of SEQ ID NO: 2 or SEQ ID NO: 32, such that mutual charge repulsion occurs between said monomer and another monomer when said monomer forms a multimeric complex with the other monomer, and (C) leucine at position 73 of SEQ ID NO:2 or 32, wherein said monomer itself or the multimeric complex thereof having an activity to promote DNA replication.