Sequence and Structure of ZANK. The amino acid sequence of the unstructured loop region of ZANK (shown in light blue in Figure 1) is shown in more detail including the addition of terminal amino acids 237-245 not present in the solved structure. This region was deleted in order to permit crystallization of the ZEBRA protein. A region with secondary structure denoted "ZANK structure" is evident in the carboxyl terminus of ZEBRA as discussed in more detail in the text. ZANK is encoded by a discrete exon corresponding precisely with the stem and loop regions shown in blue in Figure 1.