1U3Z: Crystal Structure Of Mlac Mutant Of Dimerisation Domain Of Nf-kb P50 Transcription Factor

Protein-protein interactions govern a wide range of cellular processes. Molecular recognition responsible for homodimerization and heterodimerization in the rel/NF-kappaB family of eukaryotic transcription factors relies on a small cluster of hydrophobic residues. We have carried out a structural analysis of six NF-kappaB p50 dimer interface mutants; one of them revealed a remarkable alteration. One or possibly both its mutations cause a switch into an intertwined dimer, in which the molecular partners exchange nearly half of their fold. In spite of the extensive swapping of secondary structure elements, the topology within each counterpart is preserved, with a very similar overall structure and minimal changes at the interface. Thus intertwining rescues structure and function from a destabilizing mutation. Since the mutants originate from a directed evolution experiment and are functional, the data provide an evolutionary snapshot of how a protein structure can respond to mutations while maintaining a functional molecular architecture.
PDB ID: 1U3ZDownload
MMDB ID: 29110
PDB Deposition Date: 2004/7/23
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 1.9  Å
Source Organism:
Similar Structures:
Biological Unit for 1U3Z: dimeric; determined by author
Molecular Components in 1U3Z
Label Count Molecule
Proteins (2 molecules)
Nuclear Factor Nf-kappa-b P105 Subunit(Gene symbol: Nfkb1)
Molecule annotation
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Citing MMDB