The X-ray crystal structure of the complex of the E6AP HECT domain with UbcH7 (PDB 1DF5). The HECT N lobe (blue), linker (red) and C lobe (green) are indicated. UbcH7 (magenta) was co-crystallized with the HECT domain, while ubiquitin (black) is modeled into the structure shown based on a Ubc1-ubiquitin model  (PDB 1FXT). The dashed line represents the 41 Å line-of-site between the active-site cysteines of UbcH7 and E6AP. Adapted from .