Evidence of domain swapping within the jumonji family of transcription factors
Evidence of domain swapping within the jumonji family of transcription factors
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DOI：
10.1016/s0968-0004(00)01593-0
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发表时间：
2000-06-01
影响因子：
13.8
通讯作者：
Ronne, H
中科院分区：
文献类型：
--
作者：
Balciunas, D;Ronne, H
大多数转录因子具有高度保守的DNA结合结构域，而其他地方的序列保守性较低。因此，它们通常根据其DNA结合结构域的类型被分类为家族。然而，我们发现了一个与这种观点相悖的例子：一组具有几种不同类型DNA结合域的真核转录因子似乎是从同一个祖先多肽传下来的，这表明在进化过程中存在一种域交换模式，这些蛋白质在动物、植物和真菌中都有发现。它们都共享一个结构域，该结构域首先在哺乳动物jumonji、Smcx和RBP 2蛋白中发现1，但随后发现了含有该结构域的其他几种蛋白2（图1）。值得注意的是，虽然它们都具有jumonji相似性，但它们包含几种不同类型的已知或建议的DNA结合结构域。他们中的许多人包含一个死铃声域3和一个或多个PHD fingers 4，5。它们中的一些还具有非典型的PHD指，其结构为Cys 5-His-Cys 2。三种蛋白质具有经典的锌指6，而两种蛋白质含有一个新的保守结构域（PER，“peregrin-like”;见图1），该结构域也存在于peregrin 7和其他几种真核蛋白中。PER结构域与先前提到的游隼蛋白中的PHD指相邻但不同，其C-末端部分在含有PER结构域的所有蛋白质中也是保守的。PER结构域本身具有不同于PHD指和经典锌指的指状模式中的9个保守半胱氨酸和2个组氨酸。三种拟南芥蛋白含有另一个富含苯丙氨酸和酪氨酸的新结构域（FYR，"富含FY“;见图1）。jumonji样结构域在具有不相关DNA结合结构域的蛋白质中发现的事实可能意味着它在进化过程中已经从一个蛋白质家族转移到另一个蛋白质家族。然而，我们对序列的检查显示，这种解释不太可能是正确的。我们发现，所有含有jumonji样结构域的蛋白质还共享第二个高度保守的结构域，该结构域位于靠近N末端的位置（图2）。这个新的结构域，我们称之为jmjN结构域，比C末端的结构域（以下称为jmjC结构域）短，但其序列同样保守。因此，这些蛋白质之间的相似性具有二分结构。这一发现是至关重要的，因为假设jmjC结构域具有
Most transcription factors have highly conserved DNA-binding domains, whereas there is less sequence conservation elsewhere. They are therefore usually classified into families according to their type of DNA-binding domain. However, we have found one case that defies this view; a group of eukaryotic transcription factors that possess several different kinds of DNA-binding domains seem to be descended from the same ancestral polypeptide, suggesting a pattern of domain swapping during evolution.The proteins are found in animals, plants and fungi. They all share a domain first noted in the mammalian jumonji, Smcx and RBP2 proteins1, but several other proteins that contain this domain have subsequently been found2 (Fig. 1). Remarkably, although they all share the jumonji similarity, they contain several different kinds of known or proposed DNA-binding domains. Many of them contain a dead ringer domain3 and one or more PHD fingers4, 5. Some of them also have an atypical PHD finger with the structure Cys5-His-Cys2. Three proteins have classical zinc fingers6, whereas two contain a new conserved domain (PER, for ‘peregrin-like’; see Fig. 1), which is also found in peregrin7 and several other eukaryotic proteins. The PER domain is adjacent to, but distinct from, a previously noted PHD finger in peregrin, the C-terminal part of which is also conserved in all proteins containing the PER domain. The PER domain itself has nine conserved cysteines and two histidines in a finger-like pattern that differs from both PHD fingers and classical zinc fingers. Three Arabidopsis proteins contain another new domain that is rich in phenylalanines and tyrosines (FYR, for ‘FY-rich’; see Fig. 1). The fact that the jumonji-like domain is found in proteins with unrelated DNA-binding domains could mean that it has been transferred from one protein family to another during evolution. However, our examination of the sequences revealed that this interpretation is unlikely to be correct. We found that all proteins containing the jumonji-like domain also share a second highly conserved domain, which is located close to the N terminus (Fig. 2). This new domain, which we call the jmjN domain, is shorter than the more C-terminal one, hereafter referred to as the jmjC domain, but its sequence is just as conserved. The similarity between these proteins therefore has a bipartite structure. This finding is crucial, as the assumption that the jmjC domain has