An Amyloid Organelle: Solid State NMR Evidence for Cross-Beta Assembly of Gas Vesicles

• Main Authors: Bayro, Marvin J. (Contributor), Daviso, Eugenio (Contributor), Belenky, Marina (Author), Griffin, Robert Guy (Contributor), Herzfeld, Judith (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Chemistry (Contributor), Francis Bitter Magnet Laboratory (Massachusetts Institute of Technology) (Contributor)
• Format: Article
• Language: English
• Published: American Society for Biochemistry and Molecular Biology, 2012-11-08T17:18:46Z.
• Subjects: Article
• Online Access: Get fulltext

 Functional amyloids have been identified in a wide range of organisms, taking on a variety of biological roles and being controlled by remarkable mechanisms of directed assembly. Here, we report that amyloid fibrils constitute the ribs of the buoyancy organelles of Anabaena flos-aquae. The walls of these gas-filled vesicles are known to comprise a single protein, GvpA, arranged in a low pitch helix. However, the tertiary and quaternary structures have been elusive. Using solid-state NMR correlation spectroscopy we find detailed evidence for an extended cross-β structure. This amyloid assembly helps to account for the strength and amphiphilic properties of the vesicle wall. Buoyancy organelles thus dramatically extend the scope of known functional amyloids.