FIGURE 2.
Two-dimensional (2D) structural diagram of BET bromodomain (BRD2, BRD3, and BRD4) proteins: All BET bromodomain proteins have common four alpha-helical bundles named as αZ, αA, αB, and αC. αB and αC are connected by a BC loop, and a ZA loop connects αZ, αA helices (based on x-ray crystal structure).