Properties and functions of histone variants

Abstract

Variants exist for the three core histones H3, H2A, and H2B, and for the linker histone H1, but not for the core histone H4 (Franklin and Zweidler 1977) (Table 10.1). They can differ by only a few amino acids or by the presence of additional large domains, as illustrated for the mammalian core histone variants (Fig. 10.1). Their incorporation introduces variation to chromatin composition, making chromatin a versatile template that can adapt and provide a means to regulate various DNA-based processes such as replication, transcription, recombination, and repair. In this chapter, we focus mainly on the mammalian variants, and for an evolutionary view see Talbert et al. (2012).