Conversion of a transmembrane to a water-soluble protein complex by a single point mutation

Details

Serval ID
serval:BIB_365E1C8BCC41
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Conversion of a transmembrane to a water-soluble protein complex by a single point mutation
Journal
Nature Structural Biology
Author(s)
Tsitrin  Y., Morton  C. J., el-Bez  C., Paumard  P., Velluz  M. C., Adrian  M., Dubochet  J., Parker  M. W., Lanzavecchia  S., van der Goot  F. G.
ISSN
1072-8368 (Print)
Publication state
Published
Issued date
10/2002
Volume
9
Number
10
Pages
729-33
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Oct
Abstract
Proteins exist in one of two generally incompatible states: either membrane associated or soluble. Pore-forming proteins are exceptional because they are synthesized as a water-soluble molecule but end up being located in the membrane -- that is, they are nonconstitutive membrane proteins. Here we report the pronounced effect of the single point mutation Y221G of the pore-forming toxin aerolysin. This mutation blocks the hemolytic activity of the toxin but does not affect its initial structure, its ability to bind to cell-surface receptors or its capacity to form heptamers, which constitute the channel-forming unit. The overall structure of the Y221G protein as analyzed by cryo-negative staining EM and three-dimensional reconstruction is remarkably similar to that of the wild type heptamer. The mutant protein forms a mushroom-shaped complex whose stem domain is thought to be within the membrane in the wild type toxin. In contrast to the wild type heptamer, which is a hydrophobic complex, the Y221G heptamer is fully hydrophilic. This point mutation has, therefore, converted a normally membrane-embedded toxin into a soluble complex.
Keywords
Aeromonas hydrophila Bacterial Toxins/chemistry/*genetics/metabolism Membrane Proteins/chemistry/genetics/metabolism *Point Mutation Pore Forming Cytotoxic Proteins Protein Structure, Quaternary Protein Structure, Tertiary Solubility
Pubmed
Web of science
Create date
24/01/2008 10:25
Last modification date
20/08/2019 13:24
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