Summary information and primary citation
- PDB-id
-
3n1j;
SNAP-derived features in text and
JSON formats
- Class
- DNA binding protein-DNA
- Method
- X-ray (2.65 Å)
- Summary
- Crystal structure of a stwhy2-dt32 complex
- Reference
-
Cappadocia L, Marechal A, Parent JS, Lepage E, Sygusch J,
Brisson N (2010): "Crystal
Structures of DNA-Whirly Complexes and Their Role in
Arabidopsis Organelle Genome Repair." Plant
Cell, 22, 1849-1867. doi: 10.1105/tpc.109.071399.
- Abstract
- DNA double-strand breaks are highly detrimental to all
organisms and need to be quickly and accurately repaired.
Although several proteins are known to maintain plastid and
mitochondrial genome stability in plants, little is known
about the mechanisms of DNA repair in these organelles and
the roles of specific proteins. Here, using ciprofloxacin
as a DNA damaging agent specific to the organelles, we show
that plastids and mitochondria can repair DNA double-strand
breaks through an error-prone pathway similar to the
microhomology-mediated break-induced replication observed
in humans, yeast, and bacteria. This pathway is negatively
regulated by the single-stranded DNA (ssDNA) binding
proteins from the Whirly family, thus indicating that these
proteins could contribute to the accurate repair of plant
organelle genomes. To understand the role of Whirly
proteins in this process, we solved the crystal structures
of several Whirly-DNA complexes. These reveal a
nonsequence-specific ssDNA binding mechanism in which DNA
is stabilized between domains of adjacent subunits and
rendered unavailable for duplex formation and/or protein
interactions. Our results suggest a model in which the
binding of Whirly proteins to ssDNA would favor accurate
repair of DNA double-strand breaks over an error-prone
microhomology-mediated break-induced replication repair
pathway.
