2i0n
From Proteopedia
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Structure of Dictyostelium discoideum Myosin VII SH3 domain with adjacent proline rich region
Overview
Myosins play essential roles in migration, cytokinesis, endocytosis, and, adhesion. They are composed of a large N-terminal motor domain with ATPase, and actin binding sites and C-terminal neck and tail regions, whose, functional roles and structural context in the protein are less well, characterized. The tail regions of myosins I, IV, VII, XII, and XV each, contain a putative SH3 domain that may be involved in protein-protein, interactions. SH3 domains are reported to bind proline-rich motifs, especially "PxxP" sequences, and such interactions serve regulatory, functions. The activity of Src, PI3, and Itk kinases, for example, is, regulated by intramolecular interactions between their SH3 domain and, internal proline-rich sequences. Here, we use NMR spectroscopy to reveal, the structure of a protein construct from Dictyostelium myosin VII (DdM7), spanning A1620-T1706, which contains its SH3 domain and adjacent, proline-rich region. The SH3 domain forms the signature beta-barrel, architecture found in other SH3 domains, with conserved tryptophan and, tyrosine residues forming a hydrophobic pocket known to bind "PxxP", motifs. In addition, acidic residues in the RT or n-Src loops are, available to interact with the basic anchoring residues that are typically, found in ligands or proteins that bind SH3 domains. The DdM7 SH3 differs, in the hydrophobicity of the second pocket formed by the 3(10) helix and, following beta-strand, which contains polar rather than hydrophobic side, chains. Most unusual, however, is that this domain binds its adjacent, proline-rich region at a surface remote from the region previously, identified to bind "PxxP" motifs. The interaction may affect the, orientation of the tail without sacrificing the availability of the, canonical "PxxP"-binding surface.
About this Structure
2I0N is a Single protein structure of sequence from Dictyostelium discoideum. Full crystallographic information is available from OCA.
Reference
The SH3 domain of a M7 interacts with its C-terminal proline-rich region., Wang Q, Deloia MA, Kang Y, Litchke C, Zhang N, Titus MA, Walters KJ, Protein Sci. 2007 Feb;16(2):189-96. Epub 2006 Dec 22. PMID:17189480
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