Fig 1.

Arrangement of genes of the aerobic ethanol oxidation system and its regulation in P. aeruginosa ATCC 17933. Structural genes exaA, exaBC, and genes of the pqq operon are shown in black. Genes coding for regulatory components of the ethanol oxidation system, eraSR, erbR, ercS, and ercS′, as well as ercA, which encodes a putative Fe-ADH, are shown in gray. Downstream of ercS are genes encoding a probable major facilitator superfamily (MSF) transporter, two hypothetical proteins, and a peptidyl-prolyl cis-trans isomerase (PA1996). All these genes are transcribed in the opposite direction with respect to ercS. The gene erdR (PA3604) is not shown. Mutants discussed in the text are indicated by their names.