Molecular cloning of violaxanthin de-epoxidase from romaine lettuce and expression in Escherichia coli

Citations of this article
Mendeley users who have this article in their library.


Plants need to avoid or dissipate excess light energy to protect photosystem II (PSII) from photoinhibitory damage. Higher plants have a conserved system that dissipates excess energy as heat in the light- harvesting complexes of PSII that depends on the transthylakoid ΔpH and violaxanthin de-epoxidase (VDE) activity. To our knowledge, we report the first cloning of a cDNA encoding VDE and expression of functional enzyme in Escherichia coli. VDE is nuclear encoded and has a transit peptide with characteristic features of other lumen-localized proteins. The cDNA encodes a putative polypeptide of 473 aa with a calculated molecular mass of 54,447 Da. Cleavage of the transit peptide results in a mature putative polypeptide of 348 aa with a calculated molecular mass of 39,929 Da, close to the apparent mass of the purified enzyme (43 kDa). The protein has three interesting domains including (i) a cysteine-rich region, (ii) a lipocalin signature, and (iii) a highly charged region. The E. coli expressed enzyme de-epoxidizes violaxanthin sequentially to antheraxanthin and zeaxanthin, and is inhibited by dithiothreitol, similar to VDE purified from chloroplasts. This confirms that the cDNA encodes an authentic VDE of a higher plant and is unequivocal evidence that the same enzyme catalyzes the two-step mono de-epoxidation reaction. The cloning of VDE opens new opportunities for examining the function and evolution of the xanthophyll cycle, and possibly enhancing light-stress tolerance of plants.




Bugos, R. C., & Yamamoto, H. Y. (1996). Molecular cloning of violaxanthin de-epoxidase from romaine lettuce and expression in Escherichia coli. Proceedings of the National Academy of Sciences of the United States of America, 93(13), 6320–6325.

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free