Journal article

Publication year: 2009

Pages: 220-230

Journal: Journal of Bacteriology

Volume number: 191

Issue number: 1

ISSN: 0021-9193

Open access status: Green

DOI Link: https://doi.org/10.1128/JB.00925-08

Publisher: American Society for Microbiology

Abstract: 
Photosynthetic organisms need defense systems against photooxidative stress caused by the generation of highly reactive singlet oxygen (O-1(2)). Here we show that the alternative sigma factor RpoH(II) is required for the expression of important defense factors and that deletion of rpoH(II) leads to increased sensitivity against exposure to O-1(2) and methylglyoxal in Rhodobacter sphaeroides. The gene encoding RpoH(II) is controlled by RpoE, and thereby a sigma factor cascade is constituted. We provide the first in vivo study that identifies genes controlled by an RpoH(II)-type sigma factor, which is widely distributed in the Alphaproteobacteria. RpoH(II)-dependent genes encode oxidative-stress defense systems, including proteins for the degradation of methylglyoxal, detoxification of peroxides, O-1(2) scavenging, and redox and iron homeostasis. Our experiments indicate that glutathione (GSH)-dependent mechanisms are involved in the defense against photooxidative stress in photosynthetic bacteria. Therefore, we conclude that systems pivotal for the organism's defense against photooxidative stress are strongly dependent on GSH and are specifically recognized by RpoH(II) in R. sphaeroides.

Harvard Citation style: Nuss, A., Glaeser, J. and Klug, G. (2009) RpoH(II) Activates Oxidative-Stress Defense Systems and Is Controlled by RpoE in the Singlet Oxygen-Dependent Response in Rhodobacter sphaeroides, Journal of Bacteriology, 191(1), pp. 220-230. https://doi.org/10.1128/JB.00925-08

APA Citation style: Nuss, A., Glaeser, J., & Klug, G. (2009). RpoH(II) Activates Oxidative-Stress Defense Systems and Is Controlled by RpoE in the Singlet Oxygen-Dependent Response in Rhodobacter sphaeroides. Journal of Bacteriology. 191(1), 220-230. https://doi.org/10.1128/JB.00925-08