We used DNA macroarray analysis to identify genes that respond to the status of the intracellular acetyl phosphate (acP) pool. Genes whose expression correlated negatively with the ability to synthesize acP (i.e., negatively regulated genes) function primarily in flagella biosynthesis, a result consistent with observations that we published previously [Pruss, 1994 #120]. In contrast, genes whose expression correlated positively with the ability to synthesize acP (i.e., positively regulated genes) include those for type 1 pilus assembly, colanic acid (capsule) biosynthesis, and certain stress effectors. To our knowledge, this constitutes the first report that these genes may respond to the status of the intracellular acP pool. Previously, other researchers had implicated flagella, type 1 pili, capsule and diverse stress effectors in the formation of biofilms. We therefore tested whether cells altered in their ability to metabolize acP could construct normal biofilms, and found that they could not. Cells defective for the production of acP and cells defective for the degradation of acP both could form biofilms, but these biofilms exhibited characteristics substantially different from each other and from biofilms formed by their wild-type parent. We confirmed the role of individual cell surface structures, whose expression appears to correlate with acP levels, in fim or fli mutants that cannot assemble type I pili or flagella, respectively. Thus, the information learned by expression profiling of cells defective for acP production or degradation indicates that acP may help coordinate expression of surface structures and cellular processes involved in the initial stages of wild-type biofilm development. 

Data Set

The following data set contains the normalized control (conpct) and test (tstpct) expression values, the log10 expression ratios (logratio), and P value (pln) (calculated from the LN transformed normalized raw data) for 6 experimental conditions:
ACP_ACK_AC_V_WT_LO = ackA mutant grown in TB plus 10 mM acetate vs. wildtype grown in TB
ACP_ACK_V_ACK_AC_LO = ackA mutant grown in TB vs. ackA mutant grown in TB plus 10 mM acetate
ACP_ACK_V_PTAACK_LO = ackA mutant grown in TB vs. pta-ackA mutant grown in TB
ACP_ACK_V_WT_LO = ackA mutant grown in TB vs. wildtype grown in TB
ACP_PTAACK_V_ACK_AC_LO = pta-ackA mutant grown in TB vs. ackA mutant grown in TB plus 10 mM acetate
ACP_PTAACK_V_WT_LO = pta-ackA mutant grown in TB vs. wildtype grown in TB

ackA and ackA-pta mutants (Excel: 2.9 Mb)

Supplemental Tables

Supplemental Figure 1: Amino acid utilization by wildtype, ackA, and pta ackA strains

Supplemental Figure 2: Pellicles formed by wildtype