Oxygen Control System: PrrA/PrrB two component system

This regulatory system can sense oxygen concentration and senda response, under high oxygen tension, the system remains inactive, when oxygen concentration decreases PrrB (His sensor kinase) turns active trough an autophosphorylation with help of PrrC, which transmit the signal from electron transport chain with help. Then PrrB transmit the phosphate group to PrrA response regulator that directly binds promoter and recruits RNA polymerase to start GFP transcription.

How does it work?

This genetic system consists in two modules, the first one is formed by prra, prrb and prrccoupled to B0030 RBS units, J23104 Strong constitutive promoter and B0014 Double terminator to form the transcription unit. We will evaluate the functioning of J23104, B0030 and B0014 in a new chassis. The second module consists in J54103 GFP generator (B0030 RBS + E1010 GFP + B0014 Double terminator) coupled to PpsR repressible promoter.

Inspired in…

This system is inspired in PrrBCA two component system from Rhodobacter sphaeroides, which is a master regulator that is involved in expression of approximately 850 genes, >20% of the genome (Kaplan & Eraso 2005) This system coordinately controls genes involved in the complex switch between aerobic and anaerobic lifestyles and the optimum use of reducing power. It also regulates expression of genes involved in photosynthesis, carbon dioxide fixation, nitrogen fixation, hydrogen uptake, aerotaxis, denitrification, electron transport, aerobic and anaerobic respiration, and heme biosynthesis, among others, thus emphasizing its global role (Elsen et.al 2004, Kaplan & Eraso 2005, Zeilstra-Ryalls & Kaplan 2004).

1.  Kaplan S, Eraso J, Roh JH. (2005). Interacting regulatory networks in the facultative

photosynthetic bacterium, Rhodobacter sphaeroides 2.4.1. Biochem. Soc. Trans. 33:51–55

1.  Zeilstra-Ryalls JH, Kaplan S. (2004). Oxygen intervention in the regulation of gene xpression: the photosynthetic bacterial paradigm. Cell. Mol. Life Sci. 61:417–36
2. Eraso JM, Kaplan S (2009) Regulation of gene expression by PrrA in Rhodobacter sphaeroides 2.4.1: role of polyamines and DNA topology. J Bacteriol 2009, 191(13):4341-4352.