2k6m | pdb_00002k6m
Solution Structure of Human Supervillin Headpiece
Structural highlights
Function[SVIL_HUMAN] Forms a high-affinity link between the actin cytoskeleton and the membrane. Isoform 1 (archvillin) is among the first costameric proteins to assemble during myogenesis and it contributes to myogenic membrane structure and differentiation. Appears to be involved in myosin II assembly. May modulate myosin II regulation through MLCK during cell spreading, an initial step in cell migration. May play a role in invadopodial function. Isoform 2 may be involved in modulation of focal adhesions. Supervillin-mediated down-regulation of focal adehesions involves binding to TRIP6 (By similarity).[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedVillin-type headpiece domains are compact motifs that have been used extensively as model systems for protein folding. Although the majority of headpiece domains bind actin, there are some that lack this activity. Here, we present the first NMR solution structure and (15)N-relaxation analysis of a villin-type headpiece domain natively devoid of F-actin binding activity, that of supervillin headpiece (SVHP). The structure was found to be similar to that of other headpiece domains that bind F-actin. Our NMR analysis demonstrates that SVHP lacks a conformationally flexible region (V-loop) present in all other villin-type headpiece domains and which is essential to the phosphoryl regulation of dematin headpiece. In comparing the electrostatic surface potential map of SVHP to that of other villin-type headpiece domains with significant affinity for F-actin, we identified a positive surface potential conserved among headpiece domains that bind F-actin but absent from SVHP. A single point mutation (L38K) in SVHP, which creates a similar positive surface potential, endowed SVHP with specific affinity for F-actin that is within an order of magnitude of the tightest binding headpiece domains. We propose that this effect is likely conferred by a specific buried salt bridge between headpiece and actin. As no high-resolution structural information exists for the villin-type headpiece F-actin complex, our results demonstrate that through positive mutagenesis, it is possible to design binding activity into homologous proteins without structural information of the counterpart's binding surface. How to arm a supervillin: designing F-actin binding activity into supervillin headpiece.,Brown JW, Vardar-Ulu D, McKnight CJ J Mol Biol. 2009 Oct 30;393(3):608-18. Epub 2009 Aug 14. PMID:19683541[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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