The complete amino acid sequence of histone H3 (135 residues) from the nematode Caenorhabditis elegans has been established. Microheterogeneity occurs at positions 96 and 100 of the chain. The sequences of the nematode H3 isoforms are very similar to the major chain of calf thymus H3 with which they show 4 substitutions in total. The major variant has cysteine in position 96. This is the first report of cysteine in this position in H3 from non-mammalian tissue. An exceptional methylation site has been detected at position 79. Various other sites of secondary modification are of a conservative nature.
