Apg16p interacts preferentially with Apg12p‐modified Apg5p. Total lysates were prepared from apg16Δcells (YNM124) or apg12Δapg16Δ cells (YNM115) harboring both pHA‐APG5 and pMyc‐APG16 CEN plasmids. The lysates were immunoprecipitated and analyzed as described in Figure 3. 