Amyloid fibrils of the HET-s(218-289) prion form a beta solenoid with a triangular hydrophobic core.
Prion and nonprion forms of proteins are believed to differ solely in their three-dimensional structure, which is therefore of paramount importance for the prion function. However, no atomic-resolution structure of the fibrillar state that is likely infectious has been reported to date. We present a structural model based on solid-state nuclear magnetic resonance restraints for amyloid fibrils from the prion-forming domain (residues 218 to 289) of the HET-s protein from the filamentous fungus Podospora anserina. On the basis of 134 intra- and intermolecular experimental distance restraints, we find that HET-s(218-289) forms a left-handed beta solenoid, with each molecule forming two helical windings, a compact hydrophobic core, at least 23 hydrogen bonds, three salt bridges, and two asparagine ladders. The structure is likely to have broad implications for understanding the infectious amyloid state.
Wasmer
Christian
C
Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland.
Lange
Adam
A
Van Melckebeke
Hélène
H
Siemer
Ansgar B
AB
Riek
Roland
R
Meier
Beat H
BH
D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry*; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry; D048468:Podospora / Q000737:chemistry*; D011328:Prions / Q000737:chemistry*; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
D000682:Amyloid; D005656:Fungal Proteins; C083891:HET-S protein, Podospora anserina; D010455:Peptides; D011328:Prions