Plant and algal chlorophyll synthases function in Synechocystis and interact with the YidC/Alb3 membrane insertase

Abstract

In the model cyanobacterium Synechocystis sp. PCC 6803, the terminal enzyme of chlorophyll biosynthesis, chlorophyll synthase (ChlG), forms a complex with high light‐inducible proteins, the photosystem II assembly factor Ycf39 and the YidC/Alb3/OxaI membrane insertase, co‐ordinating chlorophyll delivery with cotranslational insertion of nascent photosystem polypeptides into the membrane. To gain insight into the ubiquity of this assembly complex in higher photosynthetic organisms, we produced functional foreign chlorophyll synthases in a cyanobacterial host. Synthesis of algal and plant chlorophyll synthases allowed deletion of the otherwise essential native cyanobacterial gene. Analysis of purified protein complexes shows that the interaction with YidC is maintained for both eukaryotic enzymes, indicating that a ChlG‐YidC/Alb3 complex may be evolutionarily conserved in algae and plants.

Developmental acclimation of the thylakoid proteome to light intensity in Arabidopsis

“…Immunoblotting was performed as described by Proctor et al . (2018), with antibodies raised against PSBD, PSBA, PETA and ATPH (Agrisera, Vännäs, Sweden).…”

“…SDS-PAGE sample loading was normalised to equal amounts of chlorophyll. Immunoblotting was performed as described by Proctor et al (2018), with antibodies raised against PSBD, PSBA, PETA and ATPH (Agrisera, V€ ann€ as, Sweden). Figures 2-7.…”

Cryo-EM structure of the spinach cytochrome b6 f complex at 3.6 Å resolution

“…Elution of carotenoid and chlorophyll species was monitored by absorbance at 400, 450, 490 and 665 nm. Chlorophyll a was identified by its absorption spectra and known retention time 44 . The major carotenoid species was confirmed as 9-cis beta-carotene using a standard obtained from Sigma-Aldrich (Product number: 52824).…”

Gene Replacement in Arabidopsis Reveals Manganese Transport as an Ancient Feature of Human, Plant and Cyanobacterial UPF0016 Proteins

“…In green algae, the PAM71 homolog CGLD1 (conserved in the green lineage and diatome 1) maintained the structure and function of PSII, and contributed to its protection under photo-oxidative stress conditions ( Xing et al, 2017 ). It is well established that genes of the cyanobacterial ancestor have been transferred to the nucleus, that many of the proteins they encode are rerouted to the chloroplast ( Leister, 2003 , 2016 ; Lee and Hwang, 2018 ) and that numerous proteins can functionally replace each other ( Savidge et al, 2002 ; Sattler et al, 2003 ; Lv et al, 2009 ; Armbruster et al, 2013 ; Proctor et al, 2018 ; Yoon et al, 2019 ). Yet, what makes the evolution of the UPF0016 family particularly interesting is that it suggests all members of Eukaryota and Cyanobacteria ( Figure 1 ) might have a common ancestor, which would explain why human TMEM165 can functionally substitute for PAM71 in chloroplast membranes.…”

“…Cross-species replacement of genes in model organisms is a powerful tool with which to investigate whether the corresponding proteins retain their ancestral functions over a billion years of evolution. There are several examples in which human genes have been shown to supply the functions of their orthologous counterparts in plants ( Jha et al, 2018 ; Huber et al, 2020 ), and plant genes can frequently be replaced by the cyanobacterial ortholog or vice versa ( Savidge et al, 2002 ; Sattler et al, 2003 ; Lv et al, 2009 ; Armbruster et al, 2013 ; Proctor et al, 2018 ; Yoon et al, 2019 ). These examples of pairwise replacements can be expanded further with multiple replacement assays to gain insight into the history and evolution of gene families.…”