1l5e
The domain-swapped dimer of CV-N in solution
OverviewOverview
The structure of the potent HIV-inactivating protein cyanovirin-N was previously found by NMR to be a monomer in solution and a domain-swapped dimer by X-ray crystallography. Here we demonstrate that, in solution, CV-N can exist both in monomeric and in domain-swapped dimeric form. The dimer is a metastable, kinetically trapped structure at neutral pH and room temperature. Based on orientational NMR constraints, we show that the domain-swapped solution dimer is similar to structures in two different crystal forms, exhibiting solely a small reorientation around the hinge region. Mutation of the single proline residue in the hinge to glycine significantly stabilizes the protein in both its monomeric and dimeric forms. By contrast, mutation of the neighboring serine to proline results in an exclusively dimeric protein, caused by a drastic destabilization of the monomer.
About this StructureAbout this Structure
1L5E is a Single protein structure of sequence from Nostoc ellipsosporum. Full crystallographic information is available from OCA.
ReferenceReference
The domain-swapped dimer of cyanovirin-N is in a metastable folded state: reconciliation of X-ray and NMR structures., Barrientos LG, Louis JM, Botos I, Mori T, Han Z, O'Keefe BR, Boyd MR, Wlodawer A, Gronenborn AM, Structure. 2002 May;10(5):673-86. PMID:12015150 Page seeded by OCA on Fri May 2 23:33:29 2008