Biogenic regions of cyanobacterial thylakoids form contact sites with the plasma membrane

Structural basis for VIPP1 oligomerization and maintenance of thylakoid membrane integrity

“…Based on our high-resolution structure, we made in vivo point mutations in two conserved H1 residues previously shown to mediate lipid binding in PspA (F4E and V11E) (Jovanovic et al, 2014;McDonald et al, 2017) and then examined the effects on thylakoid architecture inside native cells using in situ cryo-electron tomography (Asano et al, 2016;Rast et al, 2019). In low light (30 µmol photons m −2 s −1 ), both mutants grew slightly slower than a wild-type control strain (WT) (Figs.…”

Relationship Between Glycerolipids and Photosynthetic Components During Recovery of Thylakoid Membranes From Nitrogen Starvation-Induced Attenuation in Synechocystis sp. PCC 6803

“…The cells grown under the continuous N-sufficient condition developed thylakoids as parallel stacks of two to four membranes along the contour of the cell membrane. In addition, some parallel sheets of thylakoid membranes formed convergence zones in close contact with the plasma membrane (Rast et al, 2019). Figure 1D for Chl a, Figure 2A for total proteins, and Figure 5A for glycerolipids were recalculated with the OD 730 data in Figure 1A.…”

“…The analysis of Synechocystis mutant that lacks the small membrane-bending protein CurT suggests that the convergence zones formed by CurT function in the assembly and accumulation of PSII, but not PSI (Heinz et al, 2016). Moreover, in situ cryo-electron tomography of Synechocystis cells revealed that the convergence membranes have many membrane-associated ribosomes and may serve as the translation site (Rast et al, 2019). Thus, disappearance and reappearance of the convergence zones with N starvation and N addition, respectively, are likely to be linked with the changes in the synthetic activity of PSII proteins under these conditions.…”

Ice-cold realities

“…Here, 3D images of cellular structures are obtained by tilting samples during data collection. An example of this approach is a study in which the thylakoids of the cyanobacterium Synechocystis were imaged; published in Nature Plants last month 6 . "With this new technology", confesses Benjamin Engel of the Max Planck Institute of Biochemistry and lead author on the paper, "we can routinely get structures of complexes within the cell at 10-30 Å resolution".…”