Small-angle neutron scattering solution structures of NADPH-dependent sulfite reductase

Murray D, Weiss K, Stanley C, Nagy G, Stroupe M, Journal of Structural Biology 213(2):107724 (2021) DOI

SASDKL6 – Sulfite reductase flavoprotein-60 reduced with 10 molar equivalents sodium dithionite

Sulfite reductase [NADPH] flavoprotein alpha-component (Assimilatory NADPH-dependent sulfite reductase flavoprotein)

MW^experimental	62	kDa
MW^expected	61	kDa

log I(s) 2.24×10^-1 2.24×10^-2 2.24×10^-3 2.24×10^-4

Sulfite reductase [NADPH] flavoprotein alpha-component (Assimilatory NADPH-dependent sulfite reductase flavoprotein) small angle scattering data

s, nm^-1

Log plot Log-Log plot

ln I(s)

Sulfite reductase [NADPH] flavoprotein alpha-component (Assimilatory NADPH-dependent sulfite reductase flavoprotein) Guinier plot

ln 2.24×10^-1 R_g: 3.4 nm 0 (3.4 nm)^-2 s²

(sR_g)²I(s)/I(0)

Sulfite reductase [NADPH] flavoprotein alpha-component (Assimilatory NADPH-dependent sulfite reductase flavoprotein) Kratky plot

1.104 0 √3 sR_g

p(r)	R_g: 3.6 nm 0 D_max: 12.2 nm

Data validation

Experimental data range

p(r) fit to data

Metric

Value

s_min D_max / π

0.6

N_Shannon

Worse

Better

Metric

Value

p_cormap

χ²

0.306
1.217

Worse

Better

Fits and models

log I(s)	s, nm^-1
+3 Δ/σ -3	s, nm^-1

SANS data from solutions of Sulfite reductase flavoprotein-60 reduced with 10 molar equivalents sodium dithionite in 50 mM KPi, 100 mM NaCl, 1 mM EDTA, pH 7.8 were collected using the EQ-SANS (BL-6) beam line (Spallation Neutron Source, Oak Ridge National Laboratory, USA) equipped with a GE linear position-sensitive detector at a sample-detector distance of 4 m and at a wavelength of λ = 0.25 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 5.00 mg/ml was measured at 8°C. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

X-ray Exposure time = UNKNOWN. Number of frames = UNKNOWN

Sulfite reductase [NADPH] flavoprotein alpha-component (Assimilatory NADPH-dependent sulfite reductase flavoprotein) (SiRFP-60)
Mol. type		Protein
Organism		Escherichia coli (strain K12)
Olig. state		Monomer
Mon. MW		60.7 kDa

UniProt		P38038 (53-599)
Sequence		FASTA