The NH2- and COOH-terminal amino acid sequence of nuclear protein A24

The NH2- and COOH-terminal sequence of nuclear portein A24 has been determined by automatic Edman degradation and carboxypeptidase A and B digestion. Protein A24 is of interest because it is composed in part of histone 2A (Goldknofp, I.L., and Busch, H., (1975) Biochem, Biophys. Res. Commun. 65, 951-960). The sequence of the first 37 NH2-terminal residues is: Met-Gln-Ile-Phe-Val-Lys-Thr-Leu-Thr-Gly-Lys-Thr-Ile-Thr-Leu-Glu-Val-Glu-Pro-Ser-Asp-Thr-Ile-Glu-Asn-Val-Lys-Ala-Lys-Ile-Gln-Asp-Lys-Glu-Gly-Ile-Pro- This sequence is not homologous to any known histone sequence. It contains regions of internal homology (italics). The COOH-terminal amino acid sequence is the same as that of histone 2A, naely: -His-His-Lys-Ala-Lys-Gly-Lys-COOH.