An atypical BRCT-BRCT interaction with the XRCC1 scaffold protein compacts human DNA Ligase IIIα within a flexible DNA repair complex.

Hammel M, Rashid I, Sverzhinsky A, Pourfarjam Y, Tsai MS, Ellenberger T, Pascal JM, Kim IK, Tainer JA, Tomkinson AE, Nucleic Acids Res (2020) Europe PMC

SASDJ82 – DNA repair protein XRCC1 - DNA Ligase IIIα complex

DNA repair protein XRCC1
DNA ligase 3 (DNA ligase III alpha)
MWexperimental 180 kDa
MWexpected 69 kDa
VPorod 675 nm3
log I(s) 1.00×104 1.00×103 1.00×102 1.00×101
DNA repair protein XRCC1 DNA ligase 3 (DNA ligase III alpha) small angle scattering data  s, nm-1
ln I(s)
DNA repair protein XRCC1 DNA ligase 3 (DNA ligase III alpha) Guinier plot ln 1.00×104 Rg: 6.2 nm 0 (6.2 nm)-2 s2
(sRg)2I(s)/I(0)
DNA repair protein XRCC1 DNA ligase 3 (DNA ligase III alpha) Kratky plot 1.104 0 √3 sRg
p(r)
DNA repair protein XRCC1 DNA ligase 3 (DNA ligase III alpha) pair distance distribution function Rg: 7.5 nm 0 Dmax: 27.9 nm

Data validation

Fits and models

log I(s)
 s, nm-1
DNA repair protein XRCC1 DNA ligase 3 (DNA ligase III alpha) BILBOMD model
DNA repair protein XRCC1 DNA ligase 3 (DNA ligase III alpha) BILBOMD model
Synchrotron SAXS data from solutions of the DNA repair protein XRCC1 - DNA Ligase IIIα complex in 50 mM Tris-HCl, pH 7.5, 100 mM NaCl, 5 mM MgCl₂, 0.2 mM PMSF, 1 mM benzamidine, were collected on the 12.3.1 (SIBYLS) beam line at the Advanced Light Source (ALS; Berkeley, CA, USA) using a Pilatus3 X 2M detector at a sample-detector distance of 2.1 m and at a wavelength of λ = 0.1127 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 50.00 μl sample at 4 mg/ml was injected at a 0.50 ml/min flow rate onto a Shodex LW-803 column at 20°C. 600 successive 3 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.

DNA repair protein XRCC1 (XRCC1)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Unknown
Mon. MW   69.5 kDa
 
UniProt   P18887 (1-633)
Sequence   FASTA
 
DNA ligase 3 (DNA ligase III alpha) (LigIIIα)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Other
Mon. MW   102.7 kDa
 
UniProt   P49916 (88-1009)
Sequence   FASTA