1o06
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Crystal structure of the Vps27p Ubiquitin Interacting Motif (UIM)
OverviewOverview
Ubiquitylation is used to target proteins into a large number of different, biological processes including proteasomal degradation, endocytosis, virus, budding, and vacuolar protein sorting (Vps). Ubiquitylated proteins are, typically recognized using one of several different conserved ubiquitin, binding modules. Here, we report the crystal structure and ubiquitin, binding properties of one such module, the ubiquitin-interacting motif, (UIM). We found that UIM peptides from several proteins involved in, endocytosis and vacuolar protein sorting including Hrs, Vps27p, Stam1, and, Eps15 bound specifically, but with modest affinity (Kd = 0.1-1 mm), to, free ubiquitin. Full affinity ubiquitin binding required the presence of, conserved acidic patches at the N and C terminus of the UIM, as well as, highly conserved central alanine and serine residues. NMR chemical shift, perturbation mapping experiments demonstrated that all of these UIM, peptides bind to the I44 surface of ubiquitin. The 1.45 A resolution, crystal structure of the second yeast Vps27p UIM (Vps27p-2) revealed that, the ubiquitin-interacting motif forms an amphipathic helix. Although, Vps27p-2 is monomeric in solution, the motif unexpectedly crystallized as, an antiparallel four-helix bundle, and the potential biological, implications of UIM oligomerization are therefore discussed.
About this StructureAbout this Structure
1O06 is a Single protein structure of sequence from [1] with ZN as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Structure and ubiquitin binding of the ubiquitin-interacting motif., Fisher RD, Wang B, Alam SL, Higginson DS, Robinson H, Sundquist WI, Hill CP, J Biol Chem. 2003 Aug 1;278(31):28976-84. Epub 2003 May 14. PMID:12750381
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