SMART: ILWEQ domain annotation

ILWEQ I/LWEQ domain

SMART accession number:	SM00307
Description:	Thought to possess an F-actin binding function.
Interpro abstract (IPR002558):	I/LWEQ domains bind to actin. It has been shown that the I/LWEQ domains from mouse talin P26039 and yeast Sla2p P33338 interact with F-actin [(PUBMED:9159132)]. The domain has four conserved blocks, the name of the domain is derived from the initial conserved amino acid of each of the four blocks [(PUBMED:9159132)]. I/LWEQ domains can be placed into four major groups based on sequence similarity: Metazoan talin. Dictyostelium discoideum (Slime mould) TalA/TalB P54633 and SLA110. Metazoan Hip1p O00291. Saccharomyces cerevisiae Sla2p P33338.
GO function:	actin binding (GO:0003779)
Family alignment:	View or

There are 167 ILWEQ domains in 167 proteins in SMART's nrdb database.

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Evolution (species in which this domain is found)
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This tree shows only several representative species. The complete taxonomic breakdown of all proteins with ILWEQ domain is also avaliable.

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Go to specific node: Caenorhabditis elegans, Homo sapiens, Mus musculus, Rattus norvegicus, Saccharomyces cerevisiae, Takifugu rubripes
Literature (relevant references for this domain)
Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.
- McCann RO, Craig SW
- The I/LWEQ module: a conserved sequence that signifies F-actin binding in functionally diverse proteins from yeast to mammals.
- Proc Natl Acad Sci U S A. 1997; 94: 5679-84
- Display abstract
- Talin is an actin-binding protein involved in integrin-mediated cell adhesion and spreading. The C-terminal 197 amino acids of vertebrate talin are 45% similar to the C-terminal residues of Sla2, a yeast protein implicated in polarized assembly of the yeast actin cytoskeleton. Talin is also homologous in this region to nematode talin, cellular slime mold filopodin, and an Sla2 homolog from nematode. Analysis of the conserved C-terminal sequences of these five proteins with BLOCK MAKER reveals a series of four blocks, which we name the I/LWEQ module after the conserved initial residues in each block. Experiments presented here show that the conserved protein domain represented by the I/LWEQ module competes quantitatively with native talin for binding to F-actin in vitro. Furthermore, the corresponding domain of Sla2 binds to both yeast and vertebrate F-actin in vitro. Mutation of one of the conserved residues in the fourth conserved block abolishes the interaction of the Sla2 I/LWEQ module with F-actin. These results establish the location of an F-actin binding domain in native talin, demonstrate that direct interaction of Sla2 with actin is a possible basis for its effect on the actin cytoskeleton in vivo, and define the I/LWEQ consensus as a new actin-binding motif.
Metabolism (metabolic pathways involving proteins which contain this domain)

Structure (3D structures containing this domain)
3D Structures of ILWEQ domains in PDB
PDB code Main view Title
1r0d Hip1r thatch domain core

1sj8 Crystal structure of talin residues 482-789

2jsw Nmr structure of the talin c-terminal actin binding site
Links (links to other resources describing this domain)
INTERPRO IPR002558

PDB code	Main view	Title
1r0d		Hip1r thatch domain core
1sj8		Crystal structure of talin residues 482-789
2jsw		Nmr structure of the talin c-terminal actin binding site

ILWEQ

3D Structures of ILWEQ domains in PDB