The Drosophila ankyrin repeat protein cactus has a predominantly α‐helical secondary structure

FEBS Letters

Ntwasa, Monde¹  Gay, Nicholas J.¹ 

[1] Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK

关键词: Drosophila cactus protein;    Ankyrin repeat;    Secondary structure;    α-Helix;   

DOI  :  10.1016/0014-5793(93)80720-F

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The cactus protein is the Drosophila homologue of the mammalian IKB family of cytoplasmic anchor proteins. We have expressed in E. coli and purified a cactus fusion protein, CACT-Bgl. CACT-Bgl protein contains the six ankyrin repeat sequences which are necessary for specific binding to the Drosophila rel family transcription factor dorsal. We show that the purified CACT-Bgl protein can bind specifically to dorsal and, using circular dichroism spectroscopy, that the protein adopts a largely α-helical secondary structure. A further analysis of the ankyrin repeat domains of cactus, using an improved secondary structure prediction program indicates that the N-terminal of the repeat will form into a loop structure and the C-terminal section into an interrupted, amphipathic α-helix. On the basis of these findings we propose that the ankyrin repeats of cactus fold together into helical bundles interconnected by diverged loops.

【 授权许可】

Unknown