Activity of lymphostatin, a lymphocyte inhibitory virulence factor of pathogenic Escherichia coli, is dependent on a cysteine protease motif.

Bease AG, Blackburn EA, Chintoan-Uta C, Webb S, Cassady-Cain RL, Stevens MP, J Mol Biol :167200 (2021) Europe PMC

SASDKM9 – Lymphostatin pH5.5

Efa1/LifA protein
MWexperimental 396 kDa
MWexpected 367 kDa
VPorod 565 nm3
log I(s) 9.18×10-2 9.18×10-3 9.18×10-4 9.18×10-5
Efa1/LifA protein small angle scattering data  s, nm-1
ln I(s)
Efa1/LifA protein Guinier plot ln 9.18×10-2 Rg: 5.9 nm 0 (5.9 nm)-2 s2
Efa1/LifA protein Kratky plot 1.104 0 3 sRg
Efa1/LifA protein pair distance distribution function Rg: 5.9 nm 0 Dmax: 19.7 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Efa1/LifA protein DAMFILT model

log I(s)
 s, nm-1

Synchrotron SAXS data of lymphostatin in 50 mM Bis-Tris, pH 5.5; 100 mM NaCl; 3% glycerol (v/v) were collected on the B21 beam line at the Diamond Light Source (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). In-line size-exclusion chromatography (SEC) SAS was employed using a 2.4 mL superdex200 3.2/300 chromatography column (GE Healthcare). 35 μl of lymphostatin solution at 1.75 mg/ml was injected at 0.075 ml/min and 620 successive 1.5 second data-frames were collected at 15°C. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the eluted buffer with no macromolecular component was subtracted.

Efa1/LifA protein (Lymphostatin)
Mol. type   Protein
Organism   Escherichia coli O127:H6 (strain E2348/69 / EPEC)
Olig. state   Monomer
Mon. MW   366.8 kDa
UniProt   B7UI23 (1-3223)
Sequence   FASTA