The structure of recombinant human annexin VI in crystals and membrane-bound.
The crystal structure of calcium-free recombinant human annexin VI was solved at a resolution of 3.2 A by using the annexin I model for Patterson search and refined to an R-factor of 19.0%. The molecule consists of two similar halves closely resembling annexin I connected by an alpha-helical segment and arranged perpendicular to each other. The calcium and membrane binding sites assigned by structural homology are therefore not located in the same plane. Analysis of the membrane-bound form of annexin VI by electron microscopy shows the two halves of the molecule coplanar with the membrane, but oriented differently to the crystal structure and suggesting a flexible arrangement. Ion channel activity has been found for annexin VI and the half molecules by electrophysiological experiments.
Benz
J
J
Max-Planck-Institut für Biochemie, Abt. Strukturforschung, Martinsried, Germany.
Bergner
A
A
Hofmann
A
A
Demange
P
P
Göttig
P
P
Liemann
S
S
Huber
R
R
Voges
D
D
D017317:Annexin A6 / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D007473:Ion Channels / Q000378:metabolism; D008854:Microscopy, Electron; D008958:Models, Molecular; D018408:Patch-Clamp Techniques; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry
D017317:Annexin A6; D007473:Ion Channels; D011994:Recombinant Proteins; D002118:Calcium