3o1h
Crystal Structure of the TorS sensor domain - TorT complex in the presence of TMAOCrystal Structure of the TorS sensor domain - TorT complex in the presence of TMAO
Structural highlights
FunctionPublication Abstract from PubMedThe osmoregulator trimethylamine-N-oxide (TMAO), commonplace in aquatic organisms, is used as the terminal electron acceptor for respiration in many bacterial species. The TMAO reductase (Tor) pathway for respiratory catalysis is controlled by a receptor system that comprises the TMAO-binding protein TorT, the sensor histidine kinase TorS, and the response regulator TorR. Here we study the TorS/TorT sensor system to gain mechanistic insight into signaling by histidine kinase receptors. We determined crystal structures for complexes of TorS sensor domains with apo TorT and with TorT (TMAO); we characterized TorS sensor associations with TorT in solution; we analyzed the thermodynamics of TMAO binding to TorT-TorS complexes; and we analyzed in vivo responses to TMAO through the TorT/TorS/TorR system to test structure-inspired hypotheses. TorS-TorT(apo) is an asymmetric 2:2 complex that binds TMAO with negative cooperativity to form a symmetric active kinase. An asymmetry-to-symmetry switch in signal transmission by the histidine kinase receptor for TMAO.,Moore JO, Hendrickson WA Structure. 2012 Apr 4;20(4):729-41. Epub 2012 Apr 3. PMID:22483119[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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