title: The tetrameric L27 domain complex as an organization platform for supramolecular assemblies.
abstract: L27 domain, initially identified in the Caenorhabditis elegans Lin-2 and Lin-7 proteins, is a protein interaction module that exists in a large family of scaffold proteins. The domain can function as an organization center of large protein assemblies required for establishment and maintenance of cell polarity. We have solved the high-resolution NMR structure of a tetrameric complex of L27 domains containing two SAP97-mLin-2 L27 domain heterodimers. Each L27 domain contains three a-helices. The first two helices of each domain are packed together to form a four-helical bundle in the heterodimer. The third helix of each L27 domain forms another four-helical bundle that assembles the two heterodimers into a tetramer. The structure of the complex provides a mechanistic explanation for L27 domain-mediated polymerization of scaffold proteins, a process that is crucial for the assembly of supramolecular complexes in asymmetric cells.
authors.affiliation: Department of Biochemistry, Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Feng
authors.forename: Jia-Fu
authors.initials: JF
authors.lastname: Long
authors.forename: Jing-Song
authors.initials: JS
authors.lastname: Fan
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Suetake
authors.forename: Mingjie
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001704:Biopolymers / Q000737:chemistry*; D017173:Caenorhabditis elegans / Q000737:chemistry*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry*; D002850:Chromatography, Gel; D015801:Helminth Proteins / Q000737:chemistry*; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry*; D051379:Mice; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid
chemical_list: D001704:Biopolymers; D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; C099173:LIN-7 protein, C elegans; C097978:Lin-2 protein, C elegans; D008565:Membrane Proteins