期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:2003
卷号:100
期号:23
页码:13286-13291
DOI:10.1073/pnas.1835776100
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:We compare the folding of representative members of a protein superfamily by experiment and simulation to investigate common features in folding mechanisms. The homeodomain superfamily of three-helical, single-domain proteins exhibits a spectrum of folding processes that spans the complete transition from concurrent secondary and tertiary structure formation (nucleation-condensation mechanism) to sequential secondary and tertiary formation (framework mechanism). The unifying factor in their mechanisms is that the transition state for (un)folding is expanded and very native-like, with the proportion and degree of formation of secondary and tertiary interactions varying. There is a transition, or slide, from the framework to nucleation-condensation mechanism with decreasing stability of the secondary structure. Thus, framework and nucleation-condensation are different manifestations of an underlying common mechanism.