Ca2+ -induced orientation of tandem collagen binding domains from clostridial collagenase ColG permits two opposing functions of collagen fibril formation and retardation.

Caviness P, Bauer R, Tanaka K, Janowska K, Roeser JR, Harter D, Sanders J, Ruth C, Matsushita O, Sakon J, FEBS J 285(17):3254-3269 (2018) Europe PMC

SASDC44 – Envelope of Col H PKD-CBD complexed with mini-collagen

ColH protein
Collagenous Peptide model [(PPG)10]
MWexperimental 37 kDa
MWexpected 33 kDa
VPorod 28 nm3
log I(s) 1.23×101 1.23×100 1.23×10-1 1.23×10-2
ColH protein Collagenous Peptide model [(PPG)10] small angle scattering data  s, nm-1
ln I(s)
ColH protein Collagenous Peptide model [(PPG)10] Guinier plot ln 1.23×101 Rg: 2.7 nm 0 (2.7 nm)-2 s2
(sRg)2I(s)/I(0)
ColH protein Collagenous Peptide model [(PPG)10] Kratky plot 1.104 0 √3 sRg
p(r)
ColH protein Collagenous Peptide model [(PPG)10] pair distance distribution function Rg: 3.0 nm 0 Dmax: 12 nm

Data validation

Fits and models

log I(s)
 s, nm-1
ColH protein Collagenous Peptide model [(PPG)10] DAMMIF model
Synchrotron SAXS data from solutions of the envelope of Col H PKD-CBD complexed with mini-collagen in 50 mM Hepes 100 mM NaCl 5 mM CaCl2, pH 7.5 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 wavelength of λ = 0.113 nm (I(s) vs s, where s = 4πsinθ/λ and 2θ is the scattering angle). Solute concentrations ranging between 1 and 5 mg/ml were measured at 10°C. 33 successive 0.300 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted and the different curves were scaled for protein concentration. The low angle data collected at lower concentrations were extrapolated to infinite dilution and merged with the higher concentration data to yield the final composite scattering curve.

Scattering for samples with concentrations of 5 mg/ml, 3 mg/ml and 1 mg/ml were averaged. Each of the average scattering curves are used to extrapolate towards infinite dilution. The scattering curve at infinite dilution was used to generate the SAXS model that represents the averaged spatial disposition of the complex in solution (DAMFILT).

ColH protein (ColH)
Mol. type   Protein
Organism   Hathewaya histolytica
Olig. state   Monomer
Mon. MW   23.9 kDa
 
UniProt   Q46085 (806-1021)
Sequence   FASTA
 
Collagenous Peptide model [(PPG)10]
Mol. type   Protein
Organism   synthetic construct
Olig. state   Trimer
Mon. MW   3.1 kDa
Sequence   FASTA