Search results for "membrane binding"
showing 4 items of 4 documents
Proton Leakage Is Sensed by IM30 and Activates IM30-Triggered Membrane Fusion
2020
The inner membrane-associated protein of 30 kDa (IM30) is crucial for the development and maintenance of the thylakoid membrane system in chloroplasts and cyanobacteria. While its exact physiological function still is under debate, it has recently been suggested that IM30 has (at least) a dual function, and the protein is involved in stabilization of the thylakoid membrane as well as in Mg2+-dependent membrane fusion. IM30 binds to negatively charged membrane lipids, preferentially at stressed membrane regions where protons potentially leak out from the thylakoid lumen into the chloroplast stroma or the cyanobacterial cytoplasm, respectively. Here we show in vitro that IM30 membrane binding…
Membrane chaperoning by members of the PspA/IM30 protein family
2017
ABSTRACTPspA, IM30 (Vipp1) and LiaH, which all belong to the PspA/IM30 protein family, form high molecular weight oligomeric structures. For all proteins membrane binding and protection of the membrane structure and integrity has been shown or postulated. Here we discuss the possible membrane chaperoning activity of PspA, IM30 and LiaH and propose that larger oligomeric structures bind to stressed membrane regions, followed by oligomer disassembly and membrane stabilization by protein monomers or smaller/different oligomeric scaffolds.
Streptolysin O: the C-terminal, tryptophan-rich domain carries functional sites for both membrane binding and self-interaction but not for stable oli…
2001
AbstractStreptolysin O belongs to the class of thiol-activated toxins, which are single chain, four-domain proteins that bind to membranes containing cholesterol and then assemble to form large oligomeric pores. Membrane binding involves a conserved tryptophan-rich sequence motif located within the C-terminally located domain 4. In contrast, sites involved in oligomerization and pore formation have been assigned to domains 1 and 3, respectively. We here examined the functional properties of domain 4, which was recombinantly expressed with an N-terminal histidine tag for purification and an additional cysteine residue for covalent labeling. The fluorescently labeled fragment readily bound to…
Oligomerization and hemolytic properties of the C-terminal domain of pyolysin, a cholesterol-dependent cytolysin
2013
Pyolysin (PLO) belongs to the homologous family of the cholesterol- dependent cytolysins (CDCs), which bind to cell membranes containing cholesterol to form oligomeric pores of large size. The CDC monomer structure consists of 4 domains. Among these, the C-terminal domain 4 has been implicated in membrane binding of the monomer, while the subsequent processes of oligomerization and membrane insertion have primarily been assigned to other domains of the molecule. Recombinantly expressed or proteolytic fragments that span domain 4 of the CDCs streptolysin O and perfringolysin O bind to membranes but fail to oligomerize, and they inhibit the activity of the respective wild-type toxins. We repo…