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Loss of Function in Zeaxanthin Epoxidase of Dunaliella tertiolecta Caused by a Single Amino Acid Mutation within the Substrate-Binding Site
- Source :
- Marine Drugs, Volume 16, Issue 11, Marine Drugs, Vol 16, Iss 11, p 418 (2018)
- Publication Year :
- 2018
- Publisher :
- MDPI AG, 2018.
-
Abstract
- The zea1 mutant of marine microalga Dunaliella tertiolecta accumulates zeaxanthin under normal growth conditions, and its phenotype has been speculated to be related to zeaxanthin epoxidase (ZEP). In this study, we isolated the ZEP gene from both wild-type D. tertiolecta and the mutant. We found that the zea1 mutant has a point mutation of the 1337th nucleotide of the ZEP sequence (a change from guanine to adenine), resulting in a change of glycine to aspartate in a highly conserved region in the catalytic domain. Similar expression levels of ZEP mRNA and protein in both wild-type and zea1 were confirmed by using qRT-PCR and western blot analysis, respectively. Additionally, the enzyme activity analysis of ZEPs in the presence of cofactors showed that the inactivation of ZEP in zea1 was not caused by deficiency in the levels of cofactors. From the predicted three-dimensional ZEP structure of zea1, we observed a conformational change on the substrate-binding site in the ZEP. A comparative analysis of the ZEP structures suggested that the conformational change induced by a single amino acid mutation might impact the interaction between the substrate and substrate-binding site, resulting in loss of zeaxanthin epoxidase function.
- Subjects :
- 0106 biological sciences
0301 basic medicine
Conformational change
Zeaxanthin epoxidase
Mutant
Pharmaceutical Science
protein structure modeling
01 natural sciences
Cofactor
03 medical and health sciences
chemistry.chemical_compound
Drug Discovery
Dunaliella tertiolecta
Nucleotide
marine microalga
Binding site
lcsh:QH301-705.5
Pharmacology, Toxicology and Pharmaceutics (miscellaneous)
chemistry.chemical_classification
biology
Point mutation
zeaxanthin epoxidase
Zeaxanthin
030104 developmental biology
lcsh:Biology (General)
chemistry
Biochemistry
biology.protein
010606 plant biology & botany
Subjects
Details
- ISSN :
- 16603397
- Volume :
- 16
- Database :
- OpenAIRE
- Journal :
- Marine Drugs
- Accession number :
- edsair.doi.dedup.....df727723a36e248f190a68ecdac58556