4OWX: Structural Basis Of Soss1 In Complex With A 12nt Ssdna

The SOSS1 complex comprising SOSSA, SOSSB1, and SOSSC senses single-stranded DNA (ssDNA) and promotes repair of DNA double-strand breaks (DSBs). But how SOSS1 is assembled and recognizes ssDNA remains elusive. The crystal structure of the N-terminal half of SOSSA (SOSSAN) in complex with SOSSB1 and SOSSC showed that SOSSAN serves as a scaffold to bind both SOSSB1 and SOSSC for assembly of the SOSS1 complex. The structures of SOSSAN/B1 in complex with a 12 nt ssDNA and SOSSAN/B1/C in complex with a 35 nt ssDNA showed that SOSSB1 interacts with both SOSSAN and ssDNA via two distinct surfaces. Recognition of ssDNA with a length of up to nine nucleotides is mediated solely by SOSSB1, whereas neither SOSSC nor SOSSAN are critical for ssDNA binding. These results reveal the structural basis of SOSS1 assembly and provide a framework for further study of the mechanism governing longer ssDNA recognition by the SOSS1 complex during DSB repair.
PDB ID: 4OWXDownload
MMDB ID: 119256
PDB Deposition Date: 2014/2/4
Updated in MMDB: 2014/12
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 4OWX: trimeric; determined by author and by software (PISA)
Molecular Components in 4OWX
Label Count Molecule
Proteins (2 molecules)
Integrator Complex Subunit 3(Gene symbol: INTS3)
Molecule annotation
Soss Complex Subunit B1(Gene symbol: NABP2)
Molecule annotation
Nucleotide(1 molecule)
DNA (5'-d(p*tp*tp*tp*tp*tp*tp*tp*tp*t)-3')
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB