High resolution AFM topographs of the Escherichia coli water channel aquaporin Z.

Details

Serval ID
serval:BIB_4D07BAD0F13F
Type
Article: article from journal or magazin.
Collection
Publications
Title
High resolution AFM topographs of the Escherichia coli water channel aquaporin Z.
Journal
The EMBO journal
Author(s)
Scheuring S., Ringler P., Borgnia M., Stahlberg H., Müller D.J., Agre P., Engel A.
ISSN
0261-4189 (Print)
ISSN-L
0261-4189
Publication state
Published
Issued date
15/09/1999
Peer-reviewed
Oui
Volume
18
Number
18
Pages
4981-4987
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
Aquaporins form a large family of membrane channels involved in osmoregulation. Electron crystallography has shown monomers to consist of six membrane spanning alpha-helices confirming sequence based predictions. Surface exposed loops are the least conserved regions, allowing differentiation of aquaporins. Atomic force microscopy was used to image the surface of aquaporin Z, the water channel of Escherichia coli. Recombinant protein with an N-terminal fragment including 10 histidines was isolated as a tetramer by Ni-affinity chromatography, and reconstituted into two-dimensional crystals with p42(1)2 symmetry. Small crystalline areas with p4 symmetry were found as well. Imaging both crystal types before and after cleavage of the N-termini allowed the cytoplasmic surface to be identified; a drastic change of the cytoplasmic surface accompanied proteolytic cleavage, while the extracellular surface morphology did not change. Flexibility mapping and volume calculations identified the longest loop at the extracellular surface. This loop exhibited a reversible force-induced conformational change.
Keywords
Amino Acid Sequence, Aquaporins/chemistry, Aquaporins/genetics, Aquaporins/ultrastructure, Crystallization, Escherichia coli/chemistry, Escherichia coli/genetics, Escherichia coli Proteins, Membrane Proteins, Microscopy, Atomic Force, Molecular Sequence Data, Protein Conformation, Protein Structure, Secondary, Recombinant Proteins/chemistry, Recombinant Proteins/genetics, Recombinant Proteins/ultrastructure, Surface Properties
Pubmed
Web of science
Open Access
Yes
Create date
09/06/2023 16:04
Last modification date
28/07/2023 6:59
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