FIGURE 4.

Overview of the factors that influence the expression of the S. acidocaldarius archaellum operon. The one component membrane factors ArnR/R1, as well as the biofilm regulator AbfR1, are positive regulators of the flaB promoter. The two kinases ArnC and ArnD (Saci_1193 and Saci_1694, respectively), here depicted as ePK (eukaryotic like protein kinase) phosphorylate ArnA and ArnB which leads to repression of flaB expression. Deletion mutants of the phosphatase PP2A have a hypermotile phenotype, however, the specific target of the phosphatase is not known.