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Nat Struct Mol Biol. 2010 Aug;17(8):971-5. doi: 10.1038/nsmb.1847. Epub 2010 Jul 18.

Structural basis for the transcriptional regulation of membrane lipid homeostasis.

Author information

1
Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.

Abstract

DesT is a transcriptional repressor that regulates the genes that control the unsaturated:saturated fatty acid ratio available for membrane lipid synthesis. DesT bound to unsaturated acyl-CoA has a high affinity for its cognate palindromic DNA-binding site, whereas DesT bound to saturated acyl-CoA does not bind this site. Structural analyses of the DesT-oleoyl-CoA-DNA and DesT-palmitoyl-CoA complexes reveal that acyl chain shape directly influences the packing of hydrophobic core residues within the DesT ligand-binding domain. These changes are propagated to the paired DNA-binding domains via conformational changes to modulate DNA binding. These structural interpretations are supported by the in vitro and in vivo characterization of site-directed mutants. The regulation of DesT by the unsaturated:saturated ratio of acyl chains rather than the concentration of a single ligand is a paradigm for understanding transcriptional regulation of membrane lipid homeostasis.

PMID:
20639888
PMCID:
PMC2935088
DOI:
10.1038/nsmb.1847
[Indexed for MEDLINE]
Free PMC Article

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