Systems Analysis of Bioenergetics and Growth of the Extreme Halophile Halobacterium salinarum
Figure 3
Arginine, proline and ornithine metabolism.
Prior to its depletion, arginine exhibits the highest uptake rate among the supplied nutrients. Most of it is deaminated to citrulline, which is then converted to ornithine and carbamoyl-phosphate (cbp). Most of the ornithine (≈95%) is transported outside through an arginine-ornithine antiporter. On the other hand, carbamoyl phosphate is primarily degraded to NH3 and CO2 in a reaction that produces ATP from ADP. Simulations show that at the beginning of growth this process produces most of the energy in the cells. The red broken arrows indicate connections to other parts of the network.