DNA BENDING AND BINDING BY METALLO-ZIPPER MODELS OF BZIP PROTEINS
DNA BENDING AND BINDING BY METALLO-ZIPPER MODELS OF BZIP PROTEINS
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DOI：
10.1021/ja00140a002
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发表时间：
1995-09
影响因子：
15
通讯作者：
C. R. Palmer;L. Sloan;J. C. Adrian;B. Cuenoud;D. N. Paolella;A. Schepartz
中科院分区：
文献类型：
--
作者：
C. R. Palmer;L. Sloan;J. C. Adrian;B. Cuenoud;D. N. Paolella;A. Schepartz
金属肽[G29T&Fe]含有酵母bZIP蛋白GCN4的DNA识别肽的两个拷贝，它们与4'-取代的双（三吡啶基）铁（II）配合物组装成二聚体。[G29Ts]2Fe含有与GCN4相同的DNA识别肽，但它具有GCN4所不具备的功能：它区分CRE （ATGACGTCAT）和AP-1 （ATGACTCAT）靶位，这两个bZIP靶位因存在或不存在单个W碱基对而不同。就CWAP-1特异性而言，[G29Ts]2Fe类似于bZIP蛋白CREB和CRE-BP1，其生物学功能需要对这两个靶点进行准确的区分。本文描述了一系列实验，探索[G29T&Fe及其同源物[G28T~]2Fe具有高cwap1特异性的分子基础。定量分析平衡解离常数表明，[G28T&FeCRE和[G29T&FeCRE配合物的稳定性不高于相应的二硫二聚物。此外，[G28Ts]2FeCRE和[G29T~]2FeCRE配合物的磷酸盐干扰模式叠加在相应的二硫二聚物配合物上。最后，螺旋相位分析表明金属肽和二硫二聚体肽都在DNA中引起等效的畸变。然而，当双（三吡啶基）铁（II）配合物被空间要求较低的联吡啶基部分取代时，crejapa -1的特异性被消除。在最近解决的GCN4结合CRE和AP-1靶点结构的背景下，分析了这一结果，使我们提出CREIAP-1特异性是由于双（三吡啶）铁（II）复合物和肽的近端区域之间的相互作用，该区域破坏了一个或多个关键的蛋白wap -1相互作用。值得注意的是，金属肽bZIP模型提出的CRE/AP1特异性机制至少部分反映了天然CRE选择性蛋白CREB和CRE- bp1所采用的机制。我们观察到，对短肽构象的微妙和间接影响可以导致DNA靶特异性的巨大变化，这为设计具有高序列特异性和高亲和力的结合DNA的令人惊讶的小分子提供了证据。将柔性聚醚链组装成离子载体的过渡金属配合物为功能合成阵列的组装提供了方便和适应性强的支架。“在我们的实验室里，我们利用过渡金属配合物作为支架，组装具有可测量功能的合成受体。”这个想法最初形成于1989年，合成了双（水杨醛二胺）镍（II）配合物。现地址：协和学院化学系。生物物理学培训计划。@ Abstract发表于1995年8月15日的《advanced ACS Abstracts》。(1) Schepartz， A.；麦克德维特，j.p.j。点。化学。SOC。1989, 1 1 1, 5976。(2) Sasaki， T.；凯泽，t.j.。点。化学。SOC。1989,1,1,380。(3)派尔，a.m.；巴顿，j。k。lnorg。化学，1990,38,413和(4)；佐佐木，t.j.。点。化学。社会科学，1991,13(1):1 - 4。(5) Schwabacher, a.w.；李,j .;雷，h。J。点。化学。SOC。陈志强，陈志强；1992,14,(6)苏亚雷斯,c;崔昌杰。点。化学。SOC。1992, 114, (7)；新海，S。四面体学报。1994,35,2915。(8)古德曼，m.s。;维斯,j .;张建军，张建军。四面体学报。1994,35(3):943。(9)琼斯，m.w.；古普塔:;Schepartz,;索普，h.h.l norg。化学，1992,31,1308。（10）用于装配功能性合成阵列的非金属支架的例子见：上野，M.；村上,a;牧野,k;莫里，t.j.。点。化学。SOC。1993,115,12575；Morii r;Simomura m;森本晃司,美国;齐藤，i.j.。点。化学。SOC。1993, 115, 1150，以及参考文献11。分子生物物理与生物化学系。目前地址：瑞士巴塞尔汽巴盖基有限公司。其中引用的参考文献。
The metallo-peptide [G29T&Fe contains two copies of the DNA recognition peptide of the yeast bZIP protein GCN4 assembled into a dimer with a 4'-substituted bis(terpyridyl)iron(II) complex. [G29Ts]2Fe contains the same DNA recognition peptide as GCN4, yet it possesses a function that GCN4 does not: it discriminates between the CRE (ATGACGTCAT) and AP-1 (ATGACTCAT) target sites, two bZIP target sites that differ by the presence or the absence of a single W base pair. In terms of its CWAP-1 specificity, [G29Ts]2Fe resembles the bZIP proteins CREB and CRE-BP1, whose biological functions require accurate discrimination of these two target sites. Here are described a series of experiments that explore the molecular basis for the high C W A P 1 specificity of [G29T&Fe and its homologue [G28T~]2Fe. Quantitative analysis of equilibrium dissociation constants reveals that the stabilities of the [G28T&FeCRE and [G29T&FeCRE complexes are no higher than those of the corresponding disulfide-dimerCRE complexes. In addition, the phosphate interference pattems of the [G28Ts]2FeCRE and [G29T~]2FeCRE complexes superpose on those of the corresponding disulfide-dimerCRE complexes. Finally, helical phasing analysis reveals that the metallo-peptides and the disulfide-dimer peptides all induce equivalent distortions in the DNA. However, CREJAP-1 specificity is eliminated when the bis(terpyridyl)iron(II) complex is replaced by a sterically less-demanding bipyridyl moiety. This result, analyzed in the context of recently solved structures of GCN4 bound to the CRE and AP-1 target sites, leads us to propose that CREIAP-1 specificity results from interactions between the bis(terpyridyl)iron(II) complex and the proximal region of the peptide that disrupts one or more critical proteiwAP-1 interactions. Remarkably, the mechanism of CRE/AP1 specificity proposed for the metallo-peptide bZIP models mirrors, at least in part, the mechanism employed by the naturally CRE-selective proteins CREB and CRE-BP1. Our observation that subtle and indirect effects on the conformation of a short peptide can lead to large changes in DNA target specificity provides evidence that it may be possible to design surprisingly small molecules that bind DNA with high sequence-specificity as well as high affinity. Introduction that assembled flexible polyether chains into ionophores capable Transition-metal complexes provide a convenient and adaptable scaffold for the assembly of functional synthetic arrays.'-I0 In our laboratory, we have exploited transition-metal complexes as scaffolds for the assembly of synthetic receptors that possess a measurable function.' This idea took form initially in 1989 with the synthesis of bis(salicylaldimine)nickel(II) complexes * To whom correspondence should be addressed. ' Current address: Department of Chemistry, Union College. 5 Department of Chemistry. I' Training Program in Biophysics. @ Abstract published in Aduance ACS Abstracts, August 15, 1995. (1) Schepartz, A.; McDevitt, J. P. J . Am. Chem. SOC. 1989, 1 1 1 , 5976. (2) Sasaki, T.; Kaiser, T. J . Am. Chem. SOC. 1989, 1 1 1 , 380. (3) Pyle, A. M.; Barton, J. K. Prog. lnorg. Chem. 1990, 38, 413 and (4) Liebeman, M.; Sasaki, T. J . Am. Chem. Soc. 1991, 113, 1470. ( 5 ) Schwabacher, A. W.; Lee, J.; Lei, H. J . Am. Chem. SOC. 1992, 114, (6) Ghadiri, M. R.; Soares, C.; Choi, C. J . Am. Chem. SOC. 1992, 114, (7) Fujimoto, K.; Shinkai, S . Tetrahedron Lett. 1994, 35, 2915. (8) Goodman, M. S . ; Weiss, J.; Hamilton, A. D. Tetrahedron Lett. 1994, 35, 8943. (9) Jones, M. W.; Gupta, N.; Schepartz, A,; Thorp, H. H. lnorg. Chem. 1992, 31, 1308. (10) For examples of nonmetallic scaffolds for the assembly of functional synthetic arrays, see: Ueno, M.; Murakami, A.; Makino, K.; Morii, T. J . Am. Chem. SOC. 1993, 115, 12575; Morii, R.; Simomura, M.; Morimoto, S.; Saito, I. J . Am. Chem. SOC. 1993, 115, 1150, as well as ref 11. Department of Molecular Biophysics and Biochemistry. Current address: Ciba-Geigy Ltd., Basel, Switzerland. references cited therein.