组蛋白共价修饰，也称组蛋白密码，包含了大量的效应/阅读模块，是一种用于调节基因组结构和功能的基本表观遗传调控机制。近年来，组蛋白密码组合阅读的研究表明，表观遗传远比我们一开始想象的要复杂的多。如，参与残基位置微调的植物同源结构域（PHD）指蛋白经常与其他阅读模块整合或协同作用，除了基本的H3K4甲基化外，还拥有很多的“读者”。本文结合植物同源结构域指蛋白的最近的，特别是结构生物学方面的一些研究，阐述了该家族的多变的结合能力以及多种重要的生物学功能。

图例: PHD脂蛋白与其他阅读模块的整合

Many keys to push: diversifying the 'readership' of plant homeodomain fingers

Yuanyuan Li and Haitao Li

Center for Structural Biology, School of Life Sciences and School of Medicine, Tsinghua University, Beijing 100084, China

Covalent histone modifications-referred to as the 'histone code', are recognized by a wealth of effector or 'reader' modules, representing one of the most fundamental epigenetic regulatory mechanisms that govern the structure and function of our genome. Recent progresses on combinatorial readout of such 'histone code' promote us to reconsider epigenetic regulation as a more complicated theme than we originally anticipated. In particular, planthomeodomain (PHD) fingers, which are evolved with fine-tuned residue composition and integrated or paired with other reader modules, display remarkably diverse 'readership' other than its founding-member target, histone H3 trimethylation on lysine 4 (H3K4me3). In this review, we detail the latest progresses of PHD finger research, especially from the perspective of structural biology, and highlight the versatile binding features and biological significance of PHD fingers.

Acta Biochim Biophys Sin (Shanghai). 2012 Jan;44(1):28-39. doi: 10.1093/abbs/gmr117.

全文: http://abbs.oxfordjournals.org/content/44/1/28.full.pdf+html