title: Gene regulation in Borrelia burgdorferi.
abstract: Borrelia burgdorferi, the spirochete that causes Lyme disease, is maintained in nature via an enzootic cycle that comprises a tick vector and a vertebrate host. Transmission from the tick to the mammal, acquisition from the mammal back to the tick, and adaptation to the two disparate environments require sensing signals and responding by regulating programs of gene expression. The molecular mechanisms utilized to effect these lifestyle changes have begun to be elucidated and feature an alternative sigma factor cascade in which RpoN (σ(54)) and RpoS (σ(S)) globally control the genes required for the different phases of the enzootic cycle. The RpoN-RpoS pathway is surprisingly complex, entailing Rrp2, an unusual enhancer-binding protein and two-component regulatory system response regulator activated by acetyl phosphate; BosR, an unorthodox DNA-binding protein; DsrA(Bb), a small noncoding RNA; and Hfq and CsrA, two RNA-binding proteins. B. burgdorferi also has a c-di-GMP signaling system that regulates the tick side of the enzootic cycle and whose function is only beginning to be appreciated.
authors.affiliation: Division of Biological Sciences and Biochemistry Program, The University of Montana, Missoula, Montana 59812, USA. scott.samuels@umontana.edu
authors.forename: D Scott
authors.initials: DS
authors.lastname: Samuels
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D025065:Borrelia burgdorferi / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008193:Lyme Disease / Q000382:microbiology*; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism; D013987:Ticks / Q000382:microbiology / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor