Deriving the ultrastructure of alpha-crustacyanin using lower-resolution structural and biophysical methods

作者：Rhys Natasha H; Wang Ming Chuan; Jowitt Thomas A; Helliwell John R^*; Grossmann J Guenter; Baldock Clair

来源：Journal of Synchrotron Radiation, 2011, 18: 79-83.

DOI：10.1107/S0909049510034977

• alpha-crustacyanin
• EM
• SAXS
• crystal packing of 1gka
• PISA
• analytical ultracentrifugation

The low-resolution structure of alpha-crustacyanin has been determined to 30 angstrom resolution using negative-stain electron microscopy (EM) with single-particle averaging. The protein, which is an assembly of eight beta-crustacyanin dimers, appears asymmetrical and rather open in layout. A model was built to the EM map using the X-ray crystallographic structure of beta-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 beta-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 alpha-crustacyanin assembly.

• 出版日期2011-1