FIG. 1.

Schematic diagram of Zta and K-bZIP. A. A schematic diagram of the known features of Zta is shown. The striped box represents the basic region, the stippled box the coiled coil, and the filled box the CT region. B. Analysis of the primary structure of K-bZIP (KbZip) and Zta using the bioinformatics program ClustalW revealed the indicated region of homology. Conserved amino acids are shown in on a light grey background, and conservative substitutions are shown on a dark grey background. The dots above the Zta sequence indicate those amino acids in the leucine zipper at “d” positions in the proposed coiled coil. The propensity of equivalent regions of Zta and K-bZIP to fold as coiled coils were investigated using the predictive program COILS and are shown as black bars below or above each sequence. The extent of the synthetic peptides used for biophysical analyses are indicated as boxes above or below each sequence. The position of the junction within the Z-K hybrid is indicated by an arrow.