Agresti A, Meneveri R, Siccardi A G, Marozzi A, Corneo G, Gaudi S, Ginelli E
Dipartimento di Biologia e Genetica per le Scienze Mediche, Università di Milano, Italy.
J Mol Biol. 1989 Feb 20;205(4):625-31. doi: 10.1016/0022-2836(89)90308-2.
The hybridization of human DNA with three non-cross-hybridizing monomers (68 bp in length) of the heterochromatic Sau3A family of DNA repeats, indicates the coexistence within a Sau3A-positive genomic block of divergent Sau3A units as well as of unrelated sequences. To gain some insight into the structure of these human heterochromatic DNA regions, three previously cloned Sau3A-positive genomic fragments (with a total length of approximately 1900 base-pairs (bp] were sequenced. The analysis of the sequences showed the presence of clustered Sau3A units with different degrees of divergence and of two DNA regions of approximately 100 bp and 291 bp in length, unrelated to the family of repeats. A consensus sequence derived from the 24 identified Sau3A monomers presents, among highly variable regions, two less variant regions of 8 bp and 10 bp in length, respectively. The Sau3A-unrelated DNA fragment 291 bp in length, used as a probe on genomic DNA digested with a series of restriction enzymes, defines a "new" family of DNA repeats possessing periodicities for HaeIII (HaeIII family). Sau3A and HaeIII repeats display a high degree of linkage in a collection of Sau3A-positive genomic recombinant phages.
人类DNA与异染色质Sau3A家族DNA重复序列的三种非交叉杂交单体（长度为68bp）杂交，表明在Sau3A阳性基因组区域内，不同的Sau3A单元以及不相关序列共存。为了深入了解这些人类异染色质DNA区域的结构，对三个先前克隆的Sau3A阳性基因组片段（总长度约为1900个碱基对（bp））进行了测序。序列分析显示存在不同程度差异的成簇Sau3A单元，以及两个长度约为100bp和291bp的与重复序列家族无关的DNA区域。从24个已鉴定的Sau3A单体推导的共有序列，在高度可变区域中分别呈现出两个长度为8bp和10bp的变异较小的区域。长度为291bp的与Sau3A无关的DNA片段，用作一系列限制酶消化的基因组DNA的探针，定义了一个具有HaeIII周期性的“新”DNA重复序列家族（HaeIII家族）。在一组Sau3A阳性基因组重组噬菌体中，Sau3A和HaeIII重复序列显示出高度的连锁关系。
