X-ray crystal structure of a TRPM assembly domain reveals an antiparallel four-stranded coiled-coil #MMPMID18782578
Fujiwara Y; Minor DL Jr
J Mol Biol 2008[Nov]; 383 (4): 854-70 PMID18782578show ga
Transient receptor potential (TRP) channels comprise a large family of tetrameric cation-selective ion channels that respond to diverse forms of sensory input. Earlier studies showed that members of the TRPM subclass possess a self-assembling tetrameric C-terminal cytoplasmic coiled-coil domain that underlies channel assembly and trafficking. Here, we present the high-resolution crystal structure of the coiled-coil domain of the channel enzyme TRPM7. The crystal structure, together with biochemical experiments, reveals an unexpected four-stranded antiparallel coiled-coil architecture that bears unique features relative to other antiparallel coiled-coils. Structural analysis indicates that a limited set of interactions encode assembly specificity determinants and uncovers a previously unnoticed segregation of TRPM assembly domains into two families that correspond with the phylogenetic divisions seen for the complete subunits. Together, the data provide a framework for understanding the mechanism of TRPM channel assembly and highlight the diversity of forms found in the coiled-coil fold.
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J+Mol+Biol 2008 ; 383 (4): 854-70
