Linker histone H1 variants

Diagram showing the linker histone H1 binding to the nucleosome

In molecular biology, the linker histone H1 is a protein family forming a critical component of eukaryotic chromatin. H1 histones bind to the linker DNA exiting from the nucleosome core particle, while the core histones (H2A, H2B, H3 and H4) form the octamer core of the nucleosome around which the DNA is wrapped.[1]

H1 forms a complex family of related proteins with distinct specificity for tissues, developmental stages, and organisms in which they are expressed.[2] Individual H1 proteins are often referred to as isoforms or variants.

The discovery of H1 variants in calf thymus preceded the discovery of core histone variants.[3][4]

Evolutionary tree of eukaryotes showing in brackets the number of known linker histone H1 variants in a given species (see original data in [2])
  1. ^ Jordan, Albert (2016-03-01). "Histone H1 in gene expression and development". Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms. 1859 (3): 429–430. doi:10.1016/j.bbagrm.2016.01.001. hdl:10261/133904. ISSN 0006-3002. PMID 26772994.
  2. ^ a b Izzo, Annalisa; Kamieniarz, Kinga; Schneider, Robert (2008-04-01). "The histone H1 family: specific members, specific functions?". Biological Chemistry. 389 (4): 333–343. doi:10.1515/BC.2008.037. ISSN 1431-6730. PMID 18208346. S2CID 1516241.
  3. ^ Kinkade, JM; Cole, RD (Dec 25, 1966). "The resolution of four lysine-rich histones derived from calf thymus". J Biol Chem. 241 (24): 5790–7. doi:10.1016/S0021-9258(18)96342-8. PMID 5954358.
  4. ^ Kinkade, JM; Cole, RD (Dec 25, 1966). "A structural comparison of different lysine-rich histones of calf thymus". J Biol Chem. 241 (24): 5798–805. doi:10.1016/S0021-9258(18)96343-X. PMID 5954359.