1ntl

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models 1ntl, resolution 30.Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Model of mouse Crry-Ig determined by solution scattering, curve fitting and homology modelling

Overview

Complement receptor-related gene/protein y (Crry) is a cell membrane-bound, regulator of complement activation found in mouse and rat. Crry contains, only short complement/consensus repeat (SCR) domains. X-ray and neutron, scattering was performed on recombinant rat Crry containing the first five, SCR domains (rCrry) and mouse Crry with five SCR domains conjugated to the, Fc fragment of mouse IgG1 (mCrry-Ig) in order to determine their solution, structures at medium resolution. The radius of gyration R(G) of rCrry was, determined to be 4.9-5.0 nm, and the R(G) of the cross-section was 1.2-1.5, nm as determined by X-ray and neutron scattering. The R(G) of mCrry-Ig was, 6.6-6.7 nm, and the R(G) of the cross-section were 2.3-2.4 nm and 1.3 nm., The maximum dimension of rCrry was 18 nm and that for mCrry-Ig was 26 nm., The neutron data indicated that rCrry and mCrry-Ig have molecular mass, values of 45,000 Da and 140,000 Da, respectively, in agreement with their, sequences, and sedimentation equilibrium data supported these, determinations. Time-derivative velocity experiments gave sedimentation, coefficients of 2.4S for rCrry and 5.4S for mCrry-Ig. A medium-resolution, model of rCrry was determined using homology models that were constructed, for the first five SCR domains of Crry from known crystal and NMR, structures, and linked by randomly generated linker peptide conformations., These trial-and-error calculations revealed a small family of extended, rCrry structures that best accounted for the scattering and, ultracentrifugation data. These were shorter than the most extended rCrry, models as the result of minor bends in the inter-SCR orientations. The, mCrry-Ig solution data were modelled starting from a fixed structure for, rCrry and the crystal structure of mouse IgG1, and was based on, conformational searches of the hinge peptide joining the mCrry and Fc, fragments. The best-fit models showed that the two mCrry antennae in, mCrry-Ig were extended from the Fc fragment. No preferred orientation of, the antennae was identified, and this indicated that the accessibility of, the antennae for the molecular targets C4b and C3b was not affected by the, covalent link to Fc. A structural comparison between Crry and complement, receptor type 1 indicated that the domain arrangement of Crry SCR 1-3 is, as extended as that of the CR1 SCR 15-17 NMR structure.

About this Structure

1NTL is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.

Reference

The extended multidomain solution structures of the complement protein Crry and its chimeric conjugate Crry-Ig by scattering, analytical ultracentrifugation and constrained modelling: implications for function and therapy., Aslam M, Guthridge JM, Hack BK, Quigg RJ, Holers VM, Perkins SJ, J Mol Biol. 2003 Jun 6;329(3):525-50. PMID:12767833

Page seeded by OCA on Tue Nov 20 22:32:40 2007