2iu6: Difference between revisions

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==Overview==
==Overview==
Dihydroxyacetone (Dha) kinases are a novel family of kinases with, signaling and metabolic functions. Here we report the x-ray structures of, the transcriptional activator DhaS and the coactivator DhaQ and, characterize their function. DhaQ is a paralog of the Dha binding Dha, kinase subunit; DhaS belongs to the family of TetR repressors although, unlike all known members of this family, it is a transcriptional, activator. DhaQ and DhaS form a stable complex that in the presence of Dha, activates transcription of the Lactococcus lactis dha operon. Dha, covalently binds to DhaQ through a hemiaminal bond with a histidine and, thereby induces a conformational change, which is propagated to the, surface via a cantilever-like structure. DhaS binding protects an inverted, repeat whose sequence is GGACACATN6ATTTGTCC and renders two GC base pairs, of the operator DNA hypersensitive to DNase I cleavage. The proximal, half-site of the inverted repeat partially overlaps with the predicted -35, consensus sequence of the dha promoter.
Dihydroxyacetone (Dha) kinases are a novel family of kinases with signaling and metabolic functions. Here we report the x-ray structures of the transcriptional activator DhaS and the coactivator DhaQ and characterize their function. DhaQ is a paralog of the Dha binding Dha kinase subunit; DhaS belongs to the family of TetR repressors although, unlike all known members of this family, it is a transcriptional activator. DhaQ and DhaS form a stable complex that in the presence of Dha activates transcription of the Lactococcus lactis dha operon. Dha covalently binds to DhaQ through a hemiaminal bond with a histidine and thereby induces a conformational change, which is propagated to the surface via a cantilever-like structure. DhaS binding protects an inverted repeat whose sequence is GGACACATN6ATTTGTCC and renders two GC base pairs of the operator DNA hypersensitive to DNase I cleavage. The proximal half-site of the inverted repeat partially overlaps with the predicted -35 consensus sequence of the dha promoter.


==About this Structure==
==About this Structure==
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[[Category: transferase]]
[[Category: transferase]]


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