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：2004
卷号：101
期号：33
页码：12183-12188
DOI：10.1073/pnas.0401245101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The x-ray crystal structure of an oligomeric miniprotein has been determined to a 1.2-A resolution by means of multiwavelength anomalous diffraction phasing with selenomethionine analogs that retain the biophysical characteristics of the native peptide. Peptide 1, comprising {alpha} and {beta} secondary structure elements with only 21 aa per monomer, associates as a discrete tetramer. The peptide adopts a previously uncharacterized quaternary structure in which {alpha} and {beta} components interact to form a tightly packed and well defined hydrophobic core. The structure provides insight into the origins of the unusual thermal stability of the oligomer. The miniprotein shares many characteristics of larger proteins, including cooperative folding, lack of 1-anilino-8-naphthalene sulfonate binding, and limited deuterium exchange, and possesses a buried surface area typical of native proteins.
