FIG 2.

Conserved amino acid motifs in MASE4, a novel sensory input domain present in the DGCs DgcX and DgcT (YcdT) and the degenerate GGDEF domain protein CdgI (YeaI). The most likely transmembrane topology of the eight hydrophobic amino acid stretches of the MASE4 domain and the GGDEF domain are shown schematically. Three highly conserved amino acid motifs in three periplasmic loops were identified by aligning DgcX, DgcT, CdgI, and two and four similar MASE4-GGDEF proteins of K. pneumoniae and E. lignolyticus, respectively (see Fig. S1 in the supplemental material). Their positions in the periplasmic loops and the respective sequence logos are indicated.