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The 5 angstrom structure of heterologously expressed plant aquaporin SoPIP2;1

Kukulski, W; Schenk, A D; Johanson, Urban LU ; Braun, T; de Groot, B L; Fotiadis, D; Kjellbom, Per LU and Engel, A (2005) In Journal of Molecular Biology 350(4). p.611-616
Abstract
SoPIP2;1 is one of the major integral proteins in spinach leaf plasma membranes. In the Xenopus oocyte expression system its water channel activity is regulated by phosphorylation at the C terminus and in the first cytosolic loop. To assess its structure, SoPIP2;1 was heterologously expressed in Pichia pastoris as a His-tagged protein and in the non-tagged form. Both forms were reconstituted into 2D crystals in the presence of lipids. Tubular crystals and double-layered crystalline sheets of non-tagged SoPIP2;1 were observed and analyzed by cryo-electron microscopy. Crystalline sheets were highly ordered and diffracted electrons to a resolution of 2.96 angstrom. High-resolution projection maps of tilted specimens provided a 3D structure at... (More)
SoPIP2;1 is one of the major integral proteins in spinach leaf plasma membranes. In the Xenopus oocyte expression system its water channel activity is regulated by phosphorylation at the C terminus and in the first cytosolic loop. To assess its structure, SoPIP2;1 was heterologously expressed in Pichia pastoris as a His-tagged protein and in the non-tagged form. Both forms were reconstituted into 2D crystals in the presence of lipids. Tubular crystals and double-layered crystalline sheets of non-tagged SoPIP2;1 were observed and analyzed by cryo-electron microscopy. Crystalline sheets were highly ordered and diffracted electrons to a resolution of 2.96 angstrom. High-resolution projection maps of tilted specimens provided a 3D structure at 5 angstrom resolution. Superposition of the SoPIP2;1 potential map with the atomic model of AQP1 demonstrates the generally well conserved overall structure of water channels. Differences concerning the extracellular loop A explain the particular crystal contacts between oppositely oriented membrane sheets of SoPIP2;1 2D crystals, and may have a function in rapid volume changes observed in stomatal guard cells or mesophyll protoplasts. This crystal packing arrangement provides access to the phosphorylated C terminus as well as the loop B phosphorylation site for studies of channel gating. (c) 2005 Elsevier Ltd. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Molecular Biology
volume
350
issue
4
pages
611 - 616
publisher
Elsevier
external identifiers
  • wos:000230446000001
  • pmid:15964017
  • scopus:20544441912
ISSN
1089-8638
DOI
10.1016/j.jmb.2005.05.001
language
English
LU publication?
yes
id
aeb2780b-8f7b-4f2a-a984-b54afec2acbc (old id 152486)
date added to LUP
2007-07-05 16:57:27
date last changed
2017-05-21 04:16:57
@article{aeb2780b-8f7b-4f2a-a984-b54afec2acbc,
  abstract     = {SoPIP2;1 is one of the major integral proteins in spinach leaf plasma membranes. In the Xenopus oocyte expression system its water channel activity is regulated by phosphorylation at the C terminus and in the first cytosolic loop. To assess its structure, SoPIP2;1 was heterologously expressed in Pichia pastoris as a His-tagged protein and in the non-tagged form. Both forms were reconstituted into 2D crystals in the presence of lipids. Tubular crystals and double-layered crystalline sheets of non-tagged SoPIP2;1 were observed and analyzed by cryo-electron microscopy. Crystalline sheets were highly ordered and diffracted electrons to a resolution of 2.96 angstrom. High-resolution projection maps of tilted specimens provided a 3D structure at 5 angstrom resolution. Superposition of the SoPIP2;1 potential map with the atomic model of AQP1 demonstrates the generally well conserved overall structure of water channels. Differences concerning the extracellular loop A explain the particular crystal contacts between oppositely oriented membrane sheets of SoPIP2;1 2D crystals, and may have a function in rapid volume changes observed in stomatal guard cells or mesophyll protoplasts. This crystal packing arrangement provides access to the phosphorylated C terminus as well as the loop B phosphorylation site for studies of channel gating. (c) 2005 Elsevier Ltd. All rights reserved.},
  author       = {Kukulski, W and Schenk, A D and Johanson, Urban and Braun, T and de Groot, B L and Fotiadis, D and Kjellbom, Per and Engel, A},
  issn         = {1089-8638},
  language     = {eng},
  number       = {4},
  pages        = {611--616},
  publisher    = {Elsevier},
  series       = {Journal of Molecular Biology},
  title        = {The 5 angstrom structure of heterologously expressed plant aquaporin SoPIP2;1},
  url          = {http://dx.doi.org/10.1016/j.jmb.2005.05.001},
  volume       = {350},
  year         = {2005},
}