Tetrahymena histone H2B. Complete amino acid sequence

Area of Science:

• Biochemistry
• Molecular Biology
• Evolutionary Biology

Background:

• Histones are crucial for DNA packaging and gene regulation.
• H2B histone is a core component of the nucleosome.
• Understanding histone sequences aids in studying protein evolution and function.

Purpose of the Study:

• To determine the complete amino acid sequence of Tetrahymena pyriformis H2B histone.
• To compare this sequence with other H2B histones for evolutionary insights.
• To discuss implications for histone structure-function relationships and protozoan phylogeny.

Main Methods:

• Purification of Tetrahymena pyriformis H2B histone.
• Enzymatic digestion using clostripain (arginine-specific protease) and chymotrypsin.
• Peptide fractionation via column chromatography.
• Amino acid sequencing using Edman degradation.

Main Results:

• The complete amino acid sequence of 119 residues for T. pyriformis H2B histone was elucidated.
• The sequence features an N-blocked proline at residue 1 and an acetylated lysine at residue 3.
• Sequence comparison with calf thymus H2B histone revealed evolutionary variations.

Conclusions:

• The determined H2B histone sequence provides a basis for understanding its role in T. pyriformis.
• Comparative analysis supports evolutionary relationships among H2B histones.
• Findings contribute to the study of protozoan phylogeny and histone functional evolution.