Fig. 4.

Ability of GacS and the stringent response to regulate relA translation. Growth curves for each strain are depicted in panel A, while translational analysis of relA is shown in panel B. Strains used were as follows: Pseudomonas sp. strain DF41 (diamonds), DF41 relA mutant (squares), DF41 relA spoT mutant (triangles), and DF41-469 (circles). Strains in panel B harbor the relA translation fusion pSWrelA. Strains were grown in M9 minimal medium supplemented with 1 mM MgSO₄ and 0.2% glucose. Note that relA expression was markedly reduced in both the SR mutants and the gacS mutant.