The effect of pyruvate on the metabolic regulation of nitrogenase activity in Rhodospirillum rubrum with darkness as switch-off effector
2010 (English)In: Microbiology, ISSN 1350-0872, E-ISSN 1465-2080Article in journal (Refereed) Submitted
Rhodospirillum rubrum, a photosynthetic diazotroph, is able to regulate nitrogenase activity in response to environmental factors such as ammonium ions or darkness – the so-called switch-off effect. This is due to reversible modification of the Fe-protein one of the two components of nitrogenase. The signal transduction pathway(s) in this regulatory mechanism is not fully understood, especially not in the response to darkness. We have previously shown that the switch-off response and metabolic state differ between cells grown with dinitrogen or glutamate as nitrogen source, although both represent poor nitrogen sources. In this study we show that addition of pyruvate to cultures grown with glutamate as nitrogen source will lead to a switch-off response that is similar to that in cultures grown with dinitrogen. The effects are related to PII protein uridylylation and GS activity. We also show that pyruvate induces de novo protein synthesis and that pyruvate formate-lyase activity is required for activity in the dark.
Place, publisher, year, edition, pages
Biochemistry and Molecular Biology
Research subject Biochemistry
IdentifiersURN: urn:nbn:se:su:diva-42159OAI: oai:DiVA.org:su-42159DiVA: diva2:351887