title: Bacterial histidine kinase as signal sensor and transducer.
abstract: Adaptation to an environmental stress is essential for cell survival in all organisms, from E. coli to human. To respond to changes in their surroundings, bacteria utilize two-component systems (TCSs), also known as histidyl-aspartyl phosphorelay (HAP) systems that consist of a histidine kinase (HK) sensor and a cognate response regulator (RR). While mammals developed complex signaling systems involving serine/threonine/tyrosine kinases in stress response mechanisms, bacterial TCS/HAP systems represent a simple but elegant prototype of signal transduction machineries. HKs are known as a seductive target for anti-bacterial therapeutic development, because of their significance in pathological virulence in some bacteria such as Salmonella enterica. Recent molecular and structural studies have shed light on the molecular basis of the signaling mechanism of HK sensor kinases. This review will focus on recent advancements in structural investigation of signal sensing and transducing mechanisms by HKs, which is critical to our understanding of bacterial biology and pathology.
authors.affiliation: Division of Molecular and Structural Biology, Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, Ont. M5G 2M9, Canada. ahmad_khorchid@yahoo.ca
authors.forename: Ahmad
authors.initials: A
authors.lastname: Khorchid
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Ikura
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D000071677:Histidine Kinase; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase