Component of the Rhodospirillum centenum Photosensory Apparatus with Structural and Functional Similarity to Methyl-Accepting Chemotaxis Protein Chemoreceptors
AUTOR(ES)
Jiang, Ze-Yu
FONTE
American Society for Microbiology
RESUMO
Photosynthetic bacteria respond to alterations in light conditions by migrating to locations that allows optimal use of light as an energy source. Studies have indicated that photosynthesis-driven electron transport functions as an attractant signal for motility among purple photosynthetic bacteria. However, it is unclear just how the motility-based signal transduction system monitors electron flow through photosynthesis-driven electron transport. Recently, we have demonstrated that the purple photosynthetic bacterium Rhodospirillum centenum is capable of rapidly moving swarm cell colonies toward infrared light as well as away from visible light. Light-driven colony motility of R. centenum has allowed us to perform genetic dissection of the signaling pathway that affects photosynthesis-driven motility. In this study, we have undertaken sequence and mutational analyses of one of the components of a signal transduction pathway, Ptr, which appears responsible for transmitting a signal from the photosynthesis-driven electron transport chain to the chemotaxis signal transduction cascade. Mutational analysis demonstrates that cells disrupted for ptr are defective in altering motility in response to light, as well as defective in light-dependent release of methanol. We present a model which proposes that Ptr senses the redox state of a component in the photosynthetic cyclic electron transport chain and that Ptr is responsible for transmitting a signal to the chemotaxis machinery to induce a photosynthesis-dependent motility response.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=94863Documentos Relacionados
- Identification of a methyl-accepting chemotaxis protein for the ribose and galactose chemoreceptors of Escherichia coli.
- Methyl-accepting chemotaxis protein III and transducer gene trg.
- Evolutionary Conservation of Methyl-Accepting Chemotaxis Protein Location in Bacteria and Archaea
- Coupling the phosphotransferase system and the methyl-accepting chemotaxis protein-dependent chemotaxis signaling pathways of Escherichia coli.
- Mutational analysis reveals functional similarity between NARX, a nitrate sensor in Escherichia coli K-12, and the methyl-accepting chemotaxis proteins.