Structural and Functional Characterization of Pseudomonas aeruginosa CupB Chaperones
Figure 1
Overall structure of P. aeruginosa CupB2 chaperone.
A) Pseudomonas aeruginosa CupB secretion system. From left to right, their biological functions are thought to be: CupB1 (pili subunit), CupB2 (periplasmic chaperone), CupB3 (outer membrane P-usher), CupB4 (periplasmic chaperone), CupB5 (a Tps-A like protein with unknown functionality), CupB6 (putative adhesin). CupB2 that is crystallographically characterized in this report is highlighted in bold. B) Crystal structure of P. aeruginosa CupB2 chaperone. The structure is colored using the rainbow color scheme implemented in Pymol [34] with the N-terminus in blue and the C-terminus in red. C) Sequence alignment between CupB2 and other CU chaperones. “*”, “:” and “.” indicate the strictly, moderately and weakly conserved residues, respectively. The signal peptide is indicated with a vertical black arrow. Secondary structure elements (box for α-helix and arrow for β-strand) are shown above the sequence alignment. F1–G1 loop is highlighted with green line. Strictly conserved Arg36 and Lys141 are highlighted with light blue box with 50% transparency. The alternating hydrophobic residues involved in the strand augmentation between chaperone and pili subunit are colored in red.