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An Engineered Aryl Azide Ligase for Site-Specific Mapping of Protein–Protein Interactions through Photo-Cross-Linking


  • This work was supported by the US National Institutes of Health (grant nos.: R01 GM072670 and P20 GM072029), the Sloan Foundation, and the Dreyfus Foundation. Samsung Corporation provided a Lee Kun Hee scholarship to Y.-A.C. We thank Susan M. Lydon for her assistance with graphics. We thank Kathleen T. Xie and Jackie Chan for help with site-directed mutagenesis experiments and Marta Fernández-Suárez for assistance and advice.


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Labeled and linked: The small-molecule binding site of Escherichia coli lipoic acid ligase was re-engineered to accept a fluorinated aryl azide probe in place of lipoic acid. Labeling with this mutant is highly specific for LAP fusion proteins. In cell lysate, FK506 binding protein was labeled and rapamycin-dependent photo-cross-linking to its interaction partner was demonstrated.