The atypical thiol–disulfide exchange protein α-DsbA2 from Wolbachia pipientis is a homotrimeric disulfide isomerase

Walden P, Whitten A, Premkumar L, Halili M, Heras B, King G, Martin J, Acta Crystallographica Section D Structural Biology 75(3):283-295 (2019) DOI

SASDC28 – Mature alpha-DsbN protein

thiol-disulfide exchange protein
MWI(0) 87 kDa
MWexpected 81 kDa
VPorod 913 nm3
log I(s) 4.84×10-2 4.84×10-3 4.84×10-4 4.84×10-5
thiol-disulfide exchange protein small angle scattering data  s, nm-1
ln I(s)
thiol-disulfide exchange protein Guinier plot ln 4.85×10-2 Rg: 2.8 nm 0 (2.8 nm)-2 s2
thiol-disulfide exchange protein Kratky plot 1.104 0 3 sRg
thiol-disulfide exchange protein pair distance distribution function Rg: 2.8 nm 0 Dmax: 8.7 nm

Data validation

Fits and models

log I(s)
 s, nm-1
thiol-disulfide exchange protein DAMMIN model

log I(s)
 s, nm-1
thiol-disulfide exchange protein CORAL model

X-ray synchrotron radiation scattering data from the mature version of alpha-DsbN from Wolbachia pipientis in 25 mM TRIS 150mM NaCl pH 7.5 were collected on the SAXS/WAXS beam line of the Australian Synchrotron (Melbourne, Australia) in a SEC-SAXS configuration using a 2D Photon counting Pilatus 1M-W pixel detector (I(s) vs s, where s = 4π sin θ/λ and 2θ is the scattering angle; λ=0.1127 nm). Approximately 100 uL of 19.8 mg/ml protein solution were injected onto a WTC-030S5 column at a flow rate of 0.5 ml/min. Five hundred successive 5 second frames were collected during the SEC-SAXS run. The peak of the elution profile occured at ~18 mins after the start of the run, and the protein scattering was taken as the average of 8 frames collected 35-75 seconds after the peak eluted (the radius of gyration dropped to ~27.6 Ang at the peak concentration of ~2.2 mg/ml, so data was averaged at a region where the concentration was lower and concentration dependent effects were not apparent). The concentration range corresponding to the averaged frames was ~0.35 - 1.15 mg/ml, and the average concentration was taken as ~0.75 mg/ml. The buffer was taken as the sum of 100 frames collected between 3-9 mins after the start of the run. The data were normalized to the intensity of the transmitted beam and radially averaged and the scattering of the solvent-blank was subtracted. The models and corresponding fits include those derived from dummy-atom modelling using DAMMIN (top) and rigid-body modelling using CORAL (bottom).

thiol-disulfide exchange protein (alpha-DsbN)
Mol. type   Protein
Organism   Wolbachia endosymbiont of Drosophila melanogaster
Olig. state   Trimer
Mon. MW   27.1 kDa
UniProt   Q73FL6 (16-252)
Sequence   FASTA