2iu4: Difference between revisions

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.

2IU4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Lactococcus_lactis Lactococcus lactis] with SO4 and HIQ as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glucokinase Glucokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.2 2.7.1.2] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2IU4 OCA].  

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