Structure of a Stand-Alone Homodimeric NRPS Condensation Domain Reveals Occlusion of the Canonical Carrier-Protein Interface

Singh J, Grant T, Gulick A, (2026) DOI

SASDZW5 – The FAA Condensation Domain, OaaC from Coprococcus Eutactus (Plipastatin synthase subunit A)

Condensation Domain from Coprococcus Eutactus
MWI(0) 113 kDa
MWexpected 108 kDa
VPorod 184 nm3
log I(s) 3.72×101 3.72×100 3.72×10-1 3.72×10-2
Condensation Domain from Coprococcus Eutactus small angle scattering data  s, nm-1
ln I(s)
Condensation Domain from Coprococcus Eutactus Guinier plot ln 3.72×101 Rg: 3.2 nm 0 (3.2 nm)-2 s2
(sRg)2I(s)/I(0)
Condensation Domain from Coprococcus Eutactus Kratky plot 1.104 0 √3 sRg
p(r)
Condensation Domain from Coprococcus Eutactus pair distance distribution function Rg: 3.2 nm 0 Dmax: 9.5 nm

Data validation

Fits and models

log I(s)
 s, nm-1
Condensation Domain from Coprococcus Eutactus GROMACS model
Synchrotron SAXS data from solutions of The FAA Condensation Domain, OaaC from Coprococcus Eutactus (Plipastatin synthase subunit A) in 10mM HEPES pH 7.5, 50mM NaCl, 0.2mM TCEP, pH 7.5 were collected on the 16-ID (LiX) beam line at the National Synchrotron Light Source II (NSLS-II) storage ring (Upton, NY, USA) using a Pilatus 1M detector at a sample-detector distance of 3.6 m and at a wavelength of λ = 0.08188 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 28.00 μl sample at 18 mg/ml was injected at a 0.35 ml/min flow rate onto a GE Superdex 200 Increase 5/150 column at 11°C. 450 successive 2 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.

Condensation Domain from Coprococcus Eutactus (OaaC)
Mol. type   Protein
Organism   Coprococcus eutactus ATCC 27759
Olig. state   Dimer
Mon. MW   54.0 kDa
 
UniProt   A0A8D9NZF9 (1-463)
Sequence   FASTA