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:35
页码:12860-12864
DOI:10.1073/pnas.0404109101
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:A highly active, monomeric chorismate mutase, obtained by topological redesign of a dimeric helical bundle enzyme from Methanococcus jannaschii, was investigated by NMR and various other biochemical techniques, including H/D exchange. Although structural disorder is generally considered to be incompatible with efficient catalysis, the monomer, unlike its natural counterpart, unexpectedly possesses all of the characteristics of a molten globule. Global conformational ordering, observed upon binding of a transition state analog, indicates that folding can be coupled to catalysis with minimal energetic penalty. These results support the suggestion that many modern enzymes might have evolved from molten globule precursors. Insofar as their structural plasticity confers relaxed substrate specificity and/or catalytic promiscuity, molten globules may also be attractive starting points for the evolution of new catalysts in the laboratory.