In the early G1 phase of the cell cycle, human HJURP is recruited to centromeres by the Mis18 complex, which consists of Mis18α, Mis18β and M18BP1. This interaction of HJURP with the Mis18 complex is essential for CENP-A deposition and the preservation of centromere identity. To identify the binding site of HJURP on the Mis18 complex, we used the amber-codon suppression method to incorporate unnatural photo-cross-linking amino acids (Bpa, p-benzoyl-L-phenylalanine; AbK, 3’-azibutyl-N-carbamoyl-lysine) and performed UV-cross-linking and mass spectrometry (MS) experiments.