Abstract
IM30/Vipp1 proteins are crucial for thylakoid membrane biogenesis in chloroplasts and cyanobacteria. A characteristic C-terminal extension distinguishes these proteins from the homologous bacterial PspA proteins, and this extension has been discussed to be key for the IM30/Vipp1 activity. Here we report that the extension of the Synechocystis IM30 protein is indispensable, and argue that both, the N-terminal PspA-domain as well as the C-terminal extension are needed in order for the IM30 protein to conduct its in vivo function. In vitro, we show that the PspA-domain of IM30 is vital for stability/folding and oligomer formation of IM30 as well as for IM30-triggered membrane fusion. In contrast, the IM30 C-terminal domain is involved in and necessary to stabilize defined contacts to negatively charged membrane surfaces, and to modulate the IM30-induced membrane fusion activity. Although the two IM30 protein domains have distinct functional roles, only together they enable IM30 to work properly.
Original language | English (US) |
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Pages (from-to) | 126-136 |
Number of pages | 11 |
Journal | Biochimica et Biophysica Acta - Bioenergetics |
Volume | 1858 |
Issue number | 2 |
DOIs | |
State | Published - Feb 1 2017 |
Bibliographical note
Publisher Copyright:© 2016 Elsevier B.V.
Keywords
- Membrane biogenesis
- Membrane fusion
- PspA
- Thylakoid membrane
- Vipp1