| Autor: |
Jennifer, Heidrich, Benedikt, Junglas, Natalia, Grytsyk, Nadja, Hellmann, Kristiane, Rusitzka, Wolfgang, Gebauer, Jürgen, Markl, Petra, Hellwig, Dirk, Schneider |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
The Journal of biological chemistry. 293(21) |
| ISSN: |
1083-351X |
| Popis: |
The “inner membrane–associated protein of 30 kDa” (IM30), also known as “vesicle-inducing protein in plastids 1” (Vipp1), is found in the majority of photosynthetic organisms that use oxygen as an energy source, and its occurrence appears to be coupled to the existence of thylakoid membranes in cyanobacteria and chloroplasts. IM30 is most likely involved in thylakoid membrane biogenesis and/or maintenance, and has recently been shown to function as a membrane fusion protein in presence of Mg(2+). However, the precise role of Mg(2+) in this process and its impact on the structure and function of IM30 remains unknown. Here, we show that Mg(2+) binds directly to IM30 with a binding affinity of ∼1 mm. Mg(2+) binding compacts the IM30 structure coupled with an increase in the thermodynamic stability of the proteins' secondary, tertiary, and quaternary structures. Furthermore, the structural alterations trigger IM30 double ring formation in vitro because of increased exposure of hydrophobic surface regions. However, in vivo Mg(2+)-triggered exposure of hydrophobic surface regions most likely modulates membrane binding and induces membrane fusion. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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