气候变化领域集成服务门户(CCPortal): Evolution of Ycf54-independent chlorophyll biosynthesis in cyanobacteria

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DOI	10.1073/pnas.2024633118
	Evolution of Ycf54-independent chlorophyll biosynthesis in cyanobacteria
	Chen G.E.; Hitchcock A.; Mareš J.; Gong Y.; Tichý M.; Pilný J.; Kovárová L.; Zdvihalová B.; Xu J.; Neil Hunter C.; Sobotka R.
发表日期	2021
ISSN	00278424
卷号	118 期号:10
英文摘要	Chlorophylls (Chls) are essential cofactors for photosynthesis. One of the least understood steps of Chl biosynthesis is formation of the fifth (E) ring, where the red substrate, magnesium protoporphyrin IX monomethyl ester, is converted to the green product, 3,8-divinyl protochlorophyllide a. In oxygenic phototrophs, this reaction is catalyzed by an oxygen-dependent cyclase, consisting of a catalytic subunit (AcsF/CycI) and an auxiliary protein, Ycf54. Deletion of Ycf54 impairs cyclase activity and results in severe Chl deficiency, but its exact role is not clear. Here, we used a Δycf54 mutant of the model cyanobacterium Synechocystis sp. PCC 6803 to generate suppressor mutations that restore normal levels of Chl. Sequencing Δycf54 revertants identified a single D219G amino acid substitution in CycI and frameshifts in slr1916, which encodes a putative esterase. Introduction of these mutations to the original Δycf54 mutant validated the suppressor effect, especially in combination. However, comprehensive analysis of the Δycf54 suppressor strains revealed that the D219G-substituted CycI is only partially active and its accumulation is misregulated, suggesting that Ycf54 controls both the level and activity of CycI. We also show that Slr1916 has Chl dephytylase activity in vitro and its inactivation up-regulates the entire Chl biosynthetic pathway, resulting in improved cyclase activity. Finally, large-scale bioinformatic analysis indicates that our laboratory evolution of Ycf54-independent CycI mimics natural evolution of AcsF in low-light–adapted ecotypes of the oceanic cyanobacteria Prochlorococcus, which lack Ycf54, providing insight into the evolutionary history of the cyclase enzyme. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Chlorophyll; Cyanobacteria; Cyclase; Microevolution; Photosynthesis
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180363
作者单位	Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, United Kingdom; Institute of Microbiology, Czech Academy of Sciences, Trebon, 37901, Czech Republic; Institute of Hydrobiology, Biology Centre of the Czech Academy of Sciences, Ceské Budejovice, 37005, Czech Republic; Faculty of Science, University of South Bohemia, Ceské Budejovice, 37005, Czech Republic; Single-Cell Center, Chinese Academy of Sciences Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
推荐引用方式 GB/T 7714	Chen G.E.,Hitchcock A.,Mareš J.,et al. Evolution of Ycf54-independent chlorophyll biosynthesis in cyanobacteria[J],2021,118(10).
APA	Chen G.E..,Hitchcock A..,Mareš J..,Gong Y..,Tichý M..,...&Sobotka R..(2021).Evolution of Ycf54-independent chlorophyll biosynthesis in cyanobacteria.Proceedings of the National Academy of Sciences of the United States of America,118(10).
MLA	Chen G.E.,et al."Evolution of Ycf54-independent chlorophyll biosynthesis in cyanobacteria".Proceedings of the National Academy of Sciences of the United States of America 118.10(2021).