ABSTRACT
Division of sister chromatids during mitosis relies on the proper formation of a kinetochore at the centromere. This specialized locus is defined by the presence of a histone H3 variant called centromere protein A (CENP-A), which is critical for the maintenance and function of the centromere. Another characteristic of centromeres are DNA motifs, such as alpha-satellite in humans, which differ between species but seemingly play an important role in centromere function. We recently reported on the highly dynamic behavior of CENP-A nucleosomes as captured using high-speed time-lapse atomic force microscopy (HS-AFM). One of the dynamic properties unique to CENP-A containing nucleosomes is the long-range translocation of the histone core along the DNA substrate. The process takes places in a stepwise fashion with the core stalling at various points along the substrate, suggesting a sequence dependence of the process. We analyzed the GC content of this sequence and found a correlation between high GC content and stalling of the CENP-A histone core. These results are presented below.
