Identification of key molecular elements in the Kar3 N-terminus. (A) Kar3 mutagenesis screen. Different Kar3 rescue constructs were transformed into the Kar3-AID mad1Δ strain and tested for viability after depletion of endogenous Kar3 by the addition of auxin. Panels show N-terminal truncations (top) and finer mapping of critical regions close to a predicted coiled-coil as functionally important (bottom). Important mutants are highlighted with arrows and dashed rectangles. (B) Sequence alignment of the identified Kar3 sequence from six budding yeast species.