Open AccessDeriving the ultrastructure of α‐crustacyanin using lower‐resolution structural and biophysical methods
Author(s) -
Rhys Natasha H.,
Wang MingChuan,
Jowitt Thomas A.,
Helliwell John R.,
Grossmann J. Günter,
Baldock Clair
Publication year - 2011
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049510034977
Subject(s) - small angle x ray scattering , scattering , resolution (logic) , analytical ultracentrifugation , crystallography , sedimentation coefficient , crystal structure , sedimentation , biological system , materials science , chemistry , physics , chemical physics , ultracentrifuge , optics , computer science , chromatography , geology , biology , nuclear magnetic resonance , paleontology , artificial intelligence , sediment , enzyme
The low‐resolution structure of α‐crustacyanin has been determined to 30 Å resolution using negative‐stain electron microscopy (EM) with single‐particle averaging. The protein, which is an assembly of eight β‐crustacyanin dimers, appears asymmetrical and rather open in layout. A model was built to the EM map using the X‐ray crystallographic structure of β‐crustacyanin guided by PISA interface analyses. The model has a theoretical sedimentation coefficient that matches well with the experimentally derived value from sedimentation velocity analytical ultracentrifugation. Additionally, the EM model has similarities to models calculated independently by rigid‐body modelling to small‐angle X‐ray scattering (SAXS) data and extracted in silico from the β‐crustacyanin crystal lattice. Theoretical X‐ray scattering from each of these models is in reasonable agreement with the experimental SAXS data and together suggest an overall design for the α‐crustacyanin assembly.