Structure of the Thomasclavelia ramosa immunoglobulin A protease reveals a modular and minimizable architecture distinct from other immunoglobulin A proteases.

Tran N, Frenette A, Holyoak T, Proc Natl Acad Sci U S A 122(35):e2503549122 (2025) Europe PMC

SASDWH3 – Thomasclavelia ramosa immunoglobulin A protease N-terminal domain

IgA protease
MWexperimental 25 kDa
MWexpected 32 kDa
VPorod 38 nm3
log I(s) 5.41×10-2 5.41×10-3 5.41×10-4 5.41×10-5
IgA protease small angle scattering data  s, nm-1
ln I(s)
IgA protease Guinier plot ln 5.42×10-2 Rg: 1.9 nm 0 (1.9 nm)-2 s2
(sRg)2I(s)/I(0)
IgA protease Kratky plot 1.104 0 √3 sRg
p(r)
IgA protease pair distance distribution function Rg: 1.9 nm 0 Dmax: 6 nm

Data validation

Fits and models

log I(s)
 s, nm-1
IgA protease ALPHAFOLD model
Synchrotron SAXS data from solutions of Thomasclavelia ramosa immunoglobulin A protease N-terminal domain in 25 mM HEPES, 1 mM TCEP, pH 7.5 were collected on the ID7A1 BioSAXS / HP-Bio Beamline beam line at the Cornell High Energy Synchrotron Source (CHESS) storage ring (Ithaca, NY, USA) using a Eiger 4M detector at a wavelength of λ = 0.11013 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). One solute concentration of 3.16 mg/ml was measured at 25°C. 15 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.

Sample detector distance = UNKNOWN

IgA protease (IgAP NTD)
Mol. type   Protein
Organism   Thomasclavelia ramosa
Olig. state   Monomer
Mon. MW   31.6 kDa
 
UniProt   Q9AES2 (31-313)
Sequence   FASTA