FIG. 5.

LI regions of CenH3s differ in sequence and length from LI of canonical H3. (A) Alignment of LI and part of the adjacent α1- and α2-helices from a selection of known CenH3 proteins (5, 13, 35, 37, 38, 39). The secondary structure for H3 is shown schematically above the sequence (20). Dashed lines mark the extent of the LI region for CenH3, found to be critical for targeting of Cid in this study. The length of LI relative to 13 amino acids in H3, is shown next to the sequence. Hyphens denote gaps. Numbers of amino acids are relative to each starting methionine. (B) Schematic of a partial canonical nucleosome (20). LI of H3 (green) forms a DNA-binding domain with LII of H4 (yellow). Protein is represented by wire backbone traces (purple for H3), and the DNA is shown in red. Secondary structures are labeled, and side chains are indicated for the loops.