4Y66: Crystal Structure Of Giardia Lamblia Hop2-mnd1 Complex

Citation:
Abstract
In meiotic DNA recombination, the Hop2-Mnd1 complex promotes Dmc1-mediated single-stranded DNA (ssDNA) invasion into homologous chromosomes to form a synaptic complex by a yet-unclear mechanism. Here, the crystal structure of Hop2-Mnd1 reveals that it forms a curved rod-like structure consisting of three leucine zippers and two kinked junctions. One end of the rod is linked to two juxtaposed winged-helix domains, and the other end is capped by extra alpha-helices to form a helical bundle-like structure. Deletion analysis shows that the helical bundle-like structure is sufficient for interacting with the Dmc1-ssDNA nucleofilament, and molecular modeling suggests that the curved rod could be accommodated into the helical groove of the nucleofilament. Remarkably, the winged-helix domains are juxtaposed at fixed relative orientation, and their binding to DNA is likely to perturb the base pairing according to molecular simulations. These findings allow us to propose a model explaining how Hop2-Mnd1 juxtaposes Dmc1-bound ssDNA with distorted recipient double-stranded DNA and thus facilitates strand invasion.
PDB ID: 4Y66Download
MMDB ID: 127960
PDB Deposition Date: 2015/2/12
Updated in MMDB: 2015/05
Experimental Method:
x-ray diffraction
Resolution: 3.2  Å
Source Organism:
Giardia lamblia ATCC 50803
Similar Structures:
Biological Unit for 4Y66: dimeric; determined by author and by software (PISA)
Molecular Components in 4Y66
Label Count Molecule
Proteins (2 molecules)
1
Mnd1
Molecule annotation
1
Putative Tbpip Family Protein
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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