2IU4

Dihydroxyacetone kinase operon co-activator Dha-DhaQ

Summary for 2IU4

• Entry DOI: 10.2210/pdb2iu4/pdb
• Related: 2IU6
• Descriptor: DIHYDROXYACETONE KINASE, SULFATE ION (3 entities in total)
• Functional Keywords: transferase, lactococcus lactis, dihydroxyacetone, co-activator, kinase
• Biological source: LACTOCOCCUS LACTIS (IL1403)
• Total number of polymer chains: 2
• Total formula weight: 75257.71

Authors

Srinivas, A.,Christen, S.,Baumann, U.,Erni, B. (deposition date: 2006-05-27, release date: 2006-06-13, Last modification date: 2011-07-13)

Primary citation

Christen, S.,Srinivas, A.,Bahler, P.,Zeller, A.,Pridmore, D.,Bieniossek, C.,Baumann, U.,Erni, B.
Regulation of the Dha Operon of Lactococcus Lactis: A Deviation from the Rule Followed by the Tetr Family of Transcription Regulators
J.Biol.Chem., 281:23129-, 2006

PubMed Abstract: 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.

PubMed: 16760471
DOI: 10.1074/JBC.M603486200

Experimental method

X-RAY DIFFRACTION (1.96 Å)