TOTAL CHEMICAL SYNTHESIS OF A UNIQUE TRANSCRIPTION FACTOR-RELATED PROTEIN - CMYC-MAX
TOTAL CHEMICAL SYNTHESIS OF A UNIQUE TRANSCRIPTION FACTOR-RELATED PROTEIN - CMYC-MAX
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DOI：
10.1021/ja00116a005
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发表时间：
1995-03-22
影响因子：
15
通讯作者：
KENT, SBH
中科院分区：
文献类型：
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作者：
CANNE, LE;FERREDAMARE, AR;KENT, SBH
cMyc和Max是通过结合形成非共价二聚体来调节基因表达的蛋白质，所述非共价二聚体结合到双链DNA的特定区域，从而激活或抑制mRNA转录。这些转录因子蛋白质中的每一种都含有类似于90个氨基酸残基的碱性/螺旋-环-螺旋/拉链（B/HLH/Z）结构域，其负责蛋白质二聚体的形成和DNA结合。cMyc和Max B/HLH/Z结构域的非共价异源二聚体被认为在体内具有重要的功能，但还不能通过常规方法（recDNA表达）获得。在这里，我们报告的总化学合成的新的共价连接的二聚体的B/HLH/Z结构域的这些转录因子的模块化战略的基础上收敛的化学连接的几个未受保护的肽段。将所得的类似于20 kDa的合成蛋白质纯化至均质，并通过电喷雾质谱法进行表征。合成的共价cMyc-Max异二聚体和共价Max同二聚体对照显示在参与mRNA转录调控的区域特异性结合DNA。获得确定的异源二聚体形式的B/HLH/Z转录因子将允许这些重要的蛋白质调节基因表达的结构和功能特性进行研究。
cMyc and Max are proteins that regulate gene expression by associating to form noncovalent dimers that bind to specific regions of double-stranded DNA, thus activating or inhibiting mRNA transcription. Each of these transcription factor proteins contains an similar to 90 amino acid residue basic/helix-loop-helix/zipper (b/HLH/Z) domain responsible for formation of the protein dimers and for DNA binding. Noncovalent heterodimers of the cMyc and Max b/HLH/Z domains are believed to be functionally important in vivo but have not been accessible by conventional means (recDNA expression). Here we report the total chemical synthesis of novel covalently-linked dimers of the b/HLH/Z domains of these transcription factors by a modular strategy based on the convergent chemical ligation of several unprotected peptide segments. The resulting similar to 20 kDa synthetic proteins were purified to homogeneity and characterized by electrospray mass spectrometry. The synthetic covalent cMyc-Max heterodimer and the covalent Max homodimer control were shown to bind DNA specifically at the region involved in the regulation of mRNA transcription. Access to defined heterodimeric forms of the b/HLH/Z transcription factors will allow the structural and functional properties of these important protein regulators of gene expression to be studied.