The mammalian chromatin is present in nucleosomes, made of histone octamers (H2A,H2B,H3,H4)₂. Mammals contain three main classes of histone H3 variants: the replicative histones (H3.1 and H3.2), the replacement histone (H3.3) and the centromeric histone (Cenp-A).
Human Histone 3 (GenBank Accession No. NM_003532), (amino acid 2-58) with N-terminal GST tag, MW = 32kDa, expressed in an Escherichia coli expression system.

Suitable substrate for histone methyltransferases

Histone proteins are basic building blocks of chromatin. H3.1 (also referred to as HIST1H3E) is mainly expressed in the S phase and is termed as replication-dependent histone. Selective methylation of H3.1 controls replication in heterochromatin area.

Formulated in 25 mM Tris-HCl, pH 8.0, 100 mM NaCl, 0.05% Tween-20, 20% glycerol and 3 mM DTT.

Thaw on ice. Upon first thaw, briefly spin tube containing enzyme to recover full content of the tube. Aliquot enzyme into single use aliquots. Store remaining undiluted enzyme in aliquots at -70°C. Note: Enzyme is very sensitive to freeze/thaw cycles.