Thermodynamics, cooperativity and stability of the tetracycline repressor (TetR) upon tetracycline binding.

Palm GJ, Buchholz I, Werten S, Girbardt B, Berndt L, Delcea M, Hinrichs W, Biochim Biophys Acta Proteins Proteom :140404 (2020) Europe PMC

SASDFE5 – Tetracycline repressor (class D), TetR(D), in complex with 5a,6-anhydrotetracycline (ATc)

Tetracycline repressor (class D)
5a,6-anhydrotetracycline
MWI(0) 43 kDa
MWexpected 47 kDa
VPorod 77 nm3
log I(s) 7.68×103 7.68×102 7.68×101 7.68×100
Tetracycline repressor (class D) 5a,6-anhydrotetracycline small angle scattering data  s, nm-1
ln I(s)
Tetracycline repressor (class D) 5a,6-anhydrotetracycline Guinier plot ln 7.68×103 Rg: 2.6 nm 0 (2.6 nm)-2 s2
(sRg)2I(s)/I(0)
Tetracycline repressor (class D) 5a,6-anhydrotetracycline Kratky plot 1.104 0 3 sRg
p(r)
Tetracycline repressor (class D) 5a,6-anhydrotetracycline pair distance distribution function Rg: 2.4 nm 0 Dmax: 6.8 nm

Data validation


Fits and models


log I(s)
 s, nm-1
Tetracycline repressor (class D) 5a,6-anhydrotetracycline PDB model

Synchrotron SAXS data from solutions of TetR(D), in complex with ATc in 50 mM Tris/HCl 150 mM NaCl 10 mM MgCl2, pH 8 were collected on the EMBL P12 beam line at PETRA III (Hamburg, Germany) using a Pilatus 2M detector at a sample-detector distance of 3.1 m and at a wavelength of λ = 0.124 nm (l(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Solute concentrations ranging between 1.4 and 1.4 mg/ml were measured at 10°C. 20 successive 0.050 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. The low angle data collected at lower concentration were merged with the highest concentration high angle data to yield the final composite scattering curve.

Tetracycline repressor (class D) (TetR(D))
Mol. type   Protein
Organism   Escherichia coli
Olig. state   Dimer
Mon. MW   23.3 kDa
 
UniProt   P0ACT4 (2-208)
Sequence   FASTA
 
5a,6-anhydrotetracycline (ATc)
Mol. type   Other
Olig. state   Dimer
Mon. MW   0.4 kDa
Chemical formula
 
PDB code   4D7M