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：2019
卷号：116
期号：29
页码：14557-14562
DOI：10.1073/pnas.1905643116
出版社：The National Academy of Sciences of the United States of America
摘要：A symmetric origin for bacterial ferredoxins was first proposed over 50 y ago, yet, to date, no functional symmetric molecule has been constructed. It is hypothesized that extant proteins have drifted from their symmetric roots via gene duplication followed by mutations. Phylogenetic analyses of extant ferredoxins support the independent evolution of N- and C-terminal sequences, thereby allowing consensus-based design of symmetric 4Fe-4S molecules. All designs bind two [4Fe-4S] clusters and exhibit strongly reducing midpoint potentials ranging from −405 to −515 mV. One of these constructs efficiently shuttles electrons through a designed metabolic pathway in Escherichia coli . These finding establish that ferredoxins consisting of a symmetric core can be used as a platform to design novel electron transfer carriers for in vivo applications. Outer-shell asymmetry increases sequence space without compromising electron transfer functionality.
关键词：consensus design ; [4Fe-4S] clusters ; bacterial ferredoxin ; protein evolution ; electron transfer
