Abstract：
:One of the critical issues regarding proteins with a four-helix bundle motif is which interactions play the major role in stabilizing this type of folded structure: the interaction among the four alpha-helices or the interaction between the loop and helix segments. To answer this question, an energetic analysis has been carried out for three proteins with a four-helix bundle--namely, methemerythrin, cytochrome b-562, and cytochrome c'. The structures on which the analysis has been made were derived from their respective crystallographic coordinates. All three proteins have long helices (16-26 residues) and most of their loops are short (3-5 residues). However, it was found in all three proteins that loop-helix interactions were stronger than helix-helix interactions. Moreover, not only the nonbonded component but also the electrostatic component of the interaction energy were dominated by loop-helix interactions rather than by interhelix interactions, although the latter involve favorable helix-dipole interactions due to the antiparallel arrangement of neighboring helices. The results of the energetic analysis indicate that the loop segments, whether they are in a theoretical model or in real proteins, play a significant role in stabilizing proteins with four-helix bundles.
journal_name
Proc Natl Acad Sci U S Aauthors
Chou KC,Maggiora GM,Scheraga HAdoi
10.1073/pnas.89.16.7315keywords:
subject
Has Abstractpub_date
1992-08-15 00:00:00pages
7315-9issue
16eissn
0027-8424issn
1091-6490journal_volume
89pub_type
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：1998-04-14 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：2001-05-08 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：2005-08-09 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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doi：10.1073/pnas.1507049112
更新日期：2015-08-04 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：1983-06-01 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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更新日期：2018-02-06 00:00:00
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
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journal_title：Proceedings of the National Academy of Sciences of the United States of America
pub_type： 杂志文章
doi：10.1073/pnas.81.24.7782
更新日期：1984-12-01 00:00:00
