FIG 5.

Proposed coarse-grained model of protein biosynthesis regulation in S. aureus. The solid lines represent the parts of the protein synthesis pathway controlled by CcpA (purple) and CodY (green). The dashed lines represent new proposed roles of these regulators in coordinating carbon and nitrogen metabolism (A) and linking metabolic gene expression with expression of translation-associated proteins (B, C). At the regulatory level, CcpA and CodY activities are coordinated at high glucose conditions. Similarly, CodY, but not CcpA, activity is correlated with the activity of Translation iModulon. CcpA and CodY also feed forward to regulate the expression of the hpf gene, which encodes a hibernation factor that can alter the fraction of active ribosomes in the cell. Through this mechanism, S. aureus may be changing the concentration of the active ribosome in response to metabolic cues.