The amino acid sequence of residues 1-104 of CTL-1, a bovine H1 histone.

The amino acid sequence of the first 104 residues of calf thymus H1 histone subfraction (CTL-1), one of the H1 histones from bovine thymus, was determined by use of peptides derived from chymotryptic and staphylococcus protease digestion. The first 35 residues differ from the corresponding regions of a rabbit thymus H1 (RTL-3) and trout H1 by 30 and 39%, respectively, while in the region between residues 36 and 104 CTL-1 differs from the rabbit histone by only 4% and from the trout histone by only 16%. Although the differences between CTL-1 and sea urchin H1 are much greater, it is still evident that the sequence between residue 36 and residue 104 has been conserved much more than that between residues 1 and 35.