text: …We next tested the effect of Es70 overproduction on the expression of the Es70-dependent usp genes (Nystrom and Neidhardt, 1996; Gustavsson et al, 2002; Nachin et al, 2005),
  which, in contrast to genes of the PSS, are positively regu-
  lated by ppGpp (Kvint et al, 2000; Gustavsson et al, 2002).