Determination of the DNA binding site of the GAL4 protein A photo-CIDNP study

Abstract

After the assignment of 1H NMR signals of aromatic side chains by means of specific deuteration, we analyzed the DNA binding site of GAL4 by measuring photo-CIDNP spectra. The results showed that Trp36 is involved in both the specific interaction with UASG and non-specific DNA binding. This residue is located inside the Cys-rich region, but outside the putative Zn-finger. The photo-CIDNP spectrum also showed that the side chains of Tyr40 and His53 are not exposed on the surface of the protein. © 1992.