Structural insights into the substrate-binding proteins Mce1A and Mce4A from Mycobacterium tuberculosis

Asthana P, Singh D, Pedersen J, Hynönen M, Sulu R, Murthy A, Laitaoja M, Jänis J, Riley L, Venkatesan R, IUCrJ 8(5) (2021) DOI

SASDJU9 – Mammalian cell entry protein 1A (Mce1A36-148)

Mce-family protein Mce1A monomer
MWexperimental 16 kDa
MWexpected 17 kDa
VPorod 29 nm3
log I(s) 2.34×10-2 2.34×10-3 2.34×10-4 2.34×10-5
Mce-family protein Mce1A monomer small angle scattering data  s, nm-1
ln I(s)
Mce-family protein Mce1A monomer Guinier plot ln 2.34×10-2 Rg: 2.1 nm 0 (2.1 nm)-2 s2
(sRg)2I(s)/I(0)
Mce-family protein Mce1A monomer Kratky plot 1.104 0 3 sRg
p(r)
Mce-family protein Mce1A monomer pair distance distribution function Rg: 2.2 nm 0 Dmax: 8.7 nm

Data validation


Fits and models


log I(s)
 s, nm-1
Mce-family protein Mce1A monomer DAMMIN model

log I(s)
 s, nm-1
Mce-family protein Mce1A monomer OTHER model

log I(s)
 s, nm-1
Mce-family protein Mce1A monomer OTHER model

Synchrotron SAXS data from solutions of Mammalian cell entry protein 1A (Mce1A36-148) in 50 mM Tris, 350 mM NaCl, 10% Glycerol, pH 8.5 were collected on the B21 beam line at the Diamond Light Source storage ring (Didcot, UK) using a Pilatus 2M detector at a wavelength of λ = 0.1 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 2.00 mg/ml was measured at 4°C. 28 successive 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.

Synchrotron SAXS data of the Mce domain of Mammalian cell entry protein (Mce) 1A collected at DLS beamline B21 using batch mode method. The molecular mass was determined using Size exclusion chromatography-multi angle light scattering (SEC-MALS) coupled to refractive index measurements and also with the SAXS data. The protein models were generated using Robetta- template based modeling by using Mce4A39-140 crystal structure as the template and fitted against the SAXS data using the in-house program.

Mce-family protein Mce1A monomer (Mce1A36-148)
Mol. type   Protein
Organism   Mycobacterium tuberculosis
Olig. state   Monomer
Mon. MW   16.8 kDa
 
UniProt   Q79FZ9 (36-148)
Sequence   FASTA