Patent ID: 7303866

Claim:
A method of identifying an agent that inhibits binding between 53BP1 (SEQ ID NO:1) or a H-3 binding fragment of 53BP1 comprising residues 1220 to 1771, 1480 to 1771, 1157 to 1634, 1480 to 1626, 1486 to 1602, 1483 to 1602, 1483 to 1624, or 1483 to 1606 of SEQ ID NO:1, and methylated Histone (H3) (SEQ ID NO: 2) capable of binding 53BP1 or a methylated 53BP1-binding fragment of histone H3 comprising residues 73-81 or 74-83, wherein said methylation corresponds to Lysine 79 of histone H3 comprising: a) contacting said 53BP1 or H3-binding fragment of 53BP1 and said H3 or 53BP1-binding fragment of histone H3 in the presence of a test agent; and b) determining whether the test agent inhibits binding between said 53BP1 or H3-binding fragment of 53BP1 and said H3 or 53BP1-binding fragment of histone H3 thereby identifying an agent which inhibits binding between 53BP1 and H3.