Callaway J E, DeLange R J, Martinson H G
Biochemistry. 1985 May 21;24(11):2686-92. doi: 10.1021/bi00332a014.
Irradiation of isolated nuclei or of a complex of histones 2A (H2A) and 2B (H2B) with ultraviolet light produces a covalent cross-link between H2A and H2B. Sequence analysis of the peptides isolated from the H2A-H2B dimer formed in solution and in nuclei demonstrated that both dimers are produced through the covalent linkage of Tyr-40 of H2B and Pro-26 of H2A. Tyrosyl residues proximal to Tyr-40 did not produce a cross-link with H2A, thereby indicating that strict conformational parameters are required for production of the H2A-H2B cross-link. We conclude that the precise juxtaposition of Tyr-40 of H2B and Pro-26 of H2A in this region of the H2A/H2B contact site is not altered upon interaction of these histones with H3 and H4 (tetramer), DNA, or other chromosomal components during nucleosome assembly.
用紫外线照射分离的细胞核或组蛋白2A（H2A）和2B（H2B）的复合物，会在H2A和H2B之间产生共价交联。对从溶液和细胞核中形成的H2A - H2B二聚体中分离出的肽段进行序列分析表明，这两种二聚体都是通过H2B的Tyr - 40与H2A的Pro - 26的共价连接产生的。靠近Tyr - 40的酪氨酰残基不会与H2A产生交联，从而表明产生H2A - H2B交联需要严格的构象参数。我们得出结论，在核小体组装过程中，这些组蛋白与H3和H4（四聚体）、DNA或其他染色体成分相互作用时，H2A/H2B接触位点这个区域中H2B的Tyr - 40与H2A的Pro - 26的精确并列不会改变。
