Wilson D S, Sheng G, Jun S, Desplan C
Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10021, USA.
Proc Natl Acad Sci U S A. 1996 Jul 9;93(14):6886-91. doi: 10.1073/pnas.93.14.6886.
Nearly all metazoan homeodomains (HDs) possess DNA binding targets that are related by the presence of a TAAT sequence. We use an in vitro genetic DNA binding site selection assay to refine our understanding of the amino acid determinants for the recognition of the TAAT site. Superimposed upon the conserved ability of metazoan HDs to recognize a TAAT core is a difference in their preference for the bases that lie immediately 3' to it. Amino acid position 50 of the HD has been shown to discriminate among these base pairs, and structural studies have suggested that water-mediated hydrogen bonds and van der Waals contacts underlie for this ability. Here, we show that each of six amino acids tested at position 50 can confer a distinct DNA binding specificity.
几乎所有后生动物的同源结构域（HDs）都拥有与TAAT序列相关的DNA结合靶点。我们使用体外遗传DNA结合位点选择试验来深化对识别TAAT位点的氨基酸决定因素的理解。后生动物HDs识别TAAT核心的保守能力之上，是它们对紧邻其3'端碱基的偏好差异。HD的第50位氨基酸已被证明能区分这些碱基对，结构研究表明，水介导的氢键和范德华接触是这种能力的基础。在这里，我们表明在第50位测试的六种氨基酸中的每一种都能赋予独特的DNA结合特异性。
