Biosynthesis of mycobacterial methylmannose polysaccharides requires a unique 1-O-methyltransferase specific for 3-O-methylated mannosides

Ripoll-Rozada J, Costa M, Manso J, Maranha A, Miranda V, Sequeira A, Ventura M, Macedo-Ribeiro S, Pereira P, Empadinhas N, Proceedings of the National Academy of Sciences :201813450 (2019) DOI

SASDDJ6 – SAM-dependent O-Methyltransferase from Mycobacterium hassiacum

Methyltransferase domain protein
MWI(0) 45 kDa
MWexpected 51 kDa
VPorod 86 nm3
log I(s) 4.25×101 4.25×100 4.25×10-1 4.25×10-2
Methyltransferase domain protein small angle scattering data  s, nm-1
ln I(s)
Methyltransferase domain protein Guinier plot ln 4.26×101 Rg: 2.6 nm 0 (2.6 nm)-2 s2
Methyltransferase domain protein Kratky plot 1.104 0 3 sRg
Methyltransferase domain protein pair distance distribution function Rg: 2.6 nm 0 Dmax: 8.5 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Methyltransferase domain protein MODELLER model

log I(s)
 s, nm-1
Methyltransferase domain protein DAMMIF model

Synchrotron SAXS data from solutions of Mycobacterium hassiacum Methyltransferase in 20 mM bis-tris propane (pH 7.5), 50 mM NaCl, 5% glycerol and 2 mM DTT were collected on the BM29 BIOSAXS beam line at the ESRF synchrotron (Grenoble, France) using a Pilatus 1M detector at a sample-detector distance of 2.867 m and at a wavelength of λ = 0.0992 nm , the range of momentum transfer 0.036 < s < 4.939 nm-1 was covered (l(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). Solute concentrations ranging between 1.6 and 12.9 mg/ml were measured at 10°C. 10 successive 1 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 concentrations were extrapolated to infinite dilution.

Methyltransferase domain protein (Methyltransferase)
Mol. type   Protein
Organism   Mycobacterium hassiacum (strain DSM 44199 / CIP 105218 / JCM 12690 / 3849)
Olig. state   Dimer
Mon. MW   25.4 kDa
UniProt   K5B7F3 (1-219)
Sequence   FASTA