Figure 3.

CENPA, CENPC, and CENPT cross-link in a single chromatin complex. (A) Close correspondence between X-ChIP of CENPA, CENPC, and CENPT data sets. X-ChIP fragments were clustered based on sequence identity, and frequency distributions of fragments within clusters between data sets were compared. Scatter plots show the regression of the number of distinct mapped merged pairs for the CENPC, CENPT, and input X-ChIP data sets on the CENPA X-ChIP data set. (B) Real-time PCR analysis of DNA obtained by sequential ChIP with indicated pairs of antibodies. The S1 primer pair was designed as described in the legend to Figure 2, and the S3 primer pair was designed from the Cen1-like (SF1 family) sequences and is also present on Chromosomes 1, 5, and 19 (Supplemental Table 1). Fold enrichment over input was calculated relative to a control noncentromeric sequence from the 5S rDNA locus.