Deciphering the allosteric regulation of mycobacterial inosine-5′-monophosphate dehydrogenase

Bulvas O, Knejzlík Z, Sýs J, Filimoněnko A, Čížková M, Clarová K, Rejman D, Kouba T, Pichová I, Nature Communications 15(1) (2024) DOI

SASDUR5 – Mycobacterium smegmatis Inosine-5'-monophosphate dehydrogenase (IMPDH) - GTP-bound form

Inosine-5'-monophosphate dehydrogenase
MWexperimental 405 kDa
MWexpected 426 kDa
VPorod 810 nm3
log I(s) 3.73×10-1 3.73×10-2 3.73×10-3 3.73×10-4
Inosine-5'-monophosphate dehydrogenase small angle scattering data  s, nm-1
ln I(s)
Inosine-5'-monophosphate dehydrogenase Guinier plot ln 3.73×10-1 Rg: 5.0 nm 0 (5.0 nm)-2 s2
(sRg)2I(s)/I(0)
Inosine-5'-monophosphate dehydrogenase Kratky plot 1.104 0 √3 sRg
p(r)
Inosine-5'-monophosphate dehydrogenase pair distance distribution function Rg: 4.9 nm 0 Dmax: 14.4 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Inosine-5'-monophosphate dehydrogenase PYMOL model
SAXS data from solutions of IMPDH - GTP-bound form - in 50 mM HEPES, 200 mM KCl, 2 mM MgCl2, 0.5 mM TCEP, pH 7.5 were collected using an Anton Paar SAXSpoint 2.0 instrument at the Institute of Biotechnology, Czech Academy of Sciences (Centre of Molecular Structure, Vestec, Czech Republic) equipped with an Eiger R 1M detector at a sample-detector distance of 0.8 m and at a wavelength of λ = 0.134 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 3.00 mg/ml was measured at 20°C. 60 successive 30.580 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.

Inosine-5'-monophosphate dehydrogenase (IMPDH)
Mol. type   Protein
Organism   Mycolicibacterium smegmatis (strain ATCC 700084 / mc(2)155)
Olig. state   Octamer
Mon. MW   53.3 kDa
 
UniProt   A0QSU3 (2-513)
Sequence   FASTA