Structural analysis of a new carotenoid-binding protein: the C-terminal domain homolog of the OCP

Dominguez-Martin M, Hammel M, Gupta S, Lechno-Yossef S, Sutter M, Rosenberg D, Chen Y, Petzold C, Ralston C, Polívka T, Kerfeld C, Scientific Reports 10(1) (2020) DOI

SASDHF6 – C-terminal domain-like carotenoid protein (CCP2), holo-tetramer

C-terminal domain-like carotenoid protein

MW^experimental	86	kDa
MW^expected	73	kDa
V^Porod	157	nm³

log I(s) 6.36×10² 6.36×10¹ 6.36×10⁰ 6.36×10^-1

C-terminal domain-like carotenoid protein small angle scattering data

s, nm^-1

Log plot Log-Log plot

ln I(s)

C-terminal domain-like carotenoid protein Guinier plot

ln 6.36×10² R_g: 3.3 nm 0 (3.3 nm)^-2 s²

(sR_g)²I(s)/I(0)

C-terminal domain-like carotenoid protein Kratky plot

1.104 0 √3 sR_g

p(r)	R_g: 3.4 nm 0 D_max: 12.1 nm

Data validation

Fits and models

log I(s)	s, nm^-1
+3 Δ/σ -3	s, nm^-1

C-terminal domain-like carotenoid protein BILBOMD model

Synchrotron SAXS data from solutions of CCP2 holo-tetramer in 10 mM potassium phosphate, 100 mM NaCl, pH 7 were collected on the 12.3.1 (SIBYLS) beam line at the Advanced Light Source (ALS; Berkeley, CA, USA) using a Pilatus3 X 2M detector at a sample-detector distance of 2.1 m and at a wavelength of λ = 0.1127 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 55.00 μl sample at 5 mg/ml was injected at a 0.50 ml/min flow rate onto a Shodex KW402.5-4F column at 20°C. 600 successive 3 second frames were collected through the SEC elution. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted from the appropriate sample elution peak frames.

Storage temperature = UNKNOWN

C-terminal domain-like carotenoid protein (CCP2)
Mol. type		Protein
Organism		Tolypothrix sp. PCC 7601
Olig. state		Tetramer
Mon. MW		18.2 kDa
Sequence		FASTA