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- Jie Liu
- *Department of Biochemistry, Weill Medical College of Cornell University, New York, NY 10021; and
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- Qi Zheng
- *Department of Biochemistry, Weill Medical College of Cornell University, New York, NY 10021; and
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- Yiqun Deng
- *Department of Biochemistry, Weill Medical College of Cornell University, New York, NY 10021; and
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- Chao-Sheng Cheng
- *Department of Biochemistry, Weill Medical College of Cornell University, New York, NY 10021; and
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- Neville R. Kallenbach
- Department of Chemistry, New York University, New York, NY 10003
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- Min Lu
- *Department of Biochemistry, Weill Medical College of Cornell University, New York, NY 10021; and
書誌事項
- 公開日
- 2006-10-17
- DOI
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- 10.1073/pnas.0604871103
- 公開者
- Proceedings of the National Academy of Sciences
この論文をさがす
説明
<jats:p>Coiled-coil proteins contain a characteristic seven-residue sequence repeat whose positions are designated a to g. The interacting surface between α-helices in a classical coiled coil is formed by interspersing nonpolar side chains at the a and d positions with hydrophilic residues at the flanking e and g positions. To explore how the chemical nature of these core amino acids dictates the overall coiled-coil architecture, we replaced all eight e and g residues in the GCN4 leucine zipper with nonpolar alanine side chains. Surprisingly, the alanine-containing mutant forms a stable α-helical heptamer in aqueous solution. The 1.25-Å resolution crystal structure of the heptamer reveals a parallel seven-stranded coiled coil enclosing a large tubular channel with an unusual heptad register shift between adjacent staggered helices. The overall geometry comprises two interleaved hydrophobic helical screws of interacting cross-sectional a and d layers that have not been seen before. Moreover, asparagines at the a positions play an essential role in heptamer formation by participating in a set of buried interhelix hydrogen bonds. These results demonstrate that heptad repeats containing four hydrophobic positions can direct assembly of complex, higher-order coiled-coil structures with rich diversity for close packing of α-helices.</jats:p>
収録刊行物
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- Proceedings of the National Academy of Sciences
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Proceedings of the National Academy of Sciences 103 (42), 15457-15462, 2006-10-17
Proceedings of the National Academy of Sciences