Structural highlights
FunctionDHAK_ECOLI Dihydroxyacetone binding subunit of the dihydroxyacetone kinase, which is responsible for phosphorylating dihydroxyacetone. Binds covalently dihydroxyacetone in hemiaminal linkage. Acts also as a corepressor of DhaR by binding to its sensor domain, in the absence of dihydroxyacetone. Publication Abstract from PubMedEscherichia coli dihydroxyacetone (Dha) kinase consists of two subunits, DhaK and DhaL. Transcription of dha operon is regulated by the DhaR transcription factor and its action is under control of the kinase subunits. DhaR is activated by interaction with DhaL while it is repressed by DhaK. We have determined the structures of DhaK and DhaL bound to the tandem GAF-like and PAS domains of the DhaR, providing an architectural model for how GAF/PAS tandem domains work together in binding protein partners. The structures reveal a mechanism of opposite transcriptional regulation by the DhaK and DhaL subunits. The kinase subunits interface with DhaR through surfaces that partially overlap with their active sites, allowing sensing of ATP- versus ADP-loaded DhaL subunit and also precluding a ternary complex between DhaK-DhaL and DhaR. The rotation of helices within the DhaR coiled-coil linker upon DhaL binding provides the mechanism for transmitting the binding signal from the GAF/PAS domains to the C-terminal DNA-binding domain. Coiled-Coil Helix Rotation Selects Repressing or Activating State of Transcriptional Regulator DhaR.,Shi R, McDonald L, Cygler M, Ekiel I Structure. 2014 Jan 14. pii: S0969-2126(13)00471-1. doi:, 10.1016/j.str.2013.11.012. PMID:24440518[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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