5XGB

Crystal structure of the PAS-GGDEF-EAL domain of PA0861 from Pseudomonas aeruginosa

Summary for 5XGB

• Entry DOI: 10.2210/pdb5xgb/pdb
• Descriptor: Uncharacterized protein (2 entities in total)
• Functional Keywords: pas domain, ggdef-eal domain, pseudomonas aeruginosa, biofilm, rbda, pa0861, transcription
• Biological source: Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)
• Total number of polymer chains: 1
• Total formula weight: 63485.31

Authors

Liu, C.,Liew, C.W.,Sreekanth, R.,Lescar, J. (deposition date: 2017-04-13, release date: 2017-12-20, Last modification date: 2024-03-27)

Primary citation

Liu, C.,Liew, C.W.,Wong, Y.H.,Tan, S.T.,Poh, W.H.,Manimekalai, M.S.S.,Rajan, S.,Xin, L.,Liang, Z.X.,Gruber, G.,Rice, S.A.,Lescar, J.
Insights into Biofilm Dispersal Regulation from the Crystal Structure of the PAS-GGDEF-EAL Region of RbdA from Pseudomonas aeruginosa.
J. Bacteriol., 200:-, 2018

PubMed Abstract: RbdA is a positive egulator of iofilm ispersal of Its cytoplasmic region (cRbdA) comprises an N-terminal Per-ARNT-Sim (PAS) domain followed by a diguanylate cyclase (GGDEF) domain and an EAL domain, whose phosphodiesterase activity is allosterically stimulated by GTP binding to the GGDEF domain. We report crystal structures of cRbdA and of two binary complexes: one with GTP/Mg bound to the GGDEF active site and one with the EAL domain bound to the c-di-GMP substrate. These structures unveil a 2-fold symmetric dimer stabilized by a closely packed N-terminal PAS domain and a noncanonical EAL dimer. The autoinhibitory switch is formed by an α-helix (S-helix) immediately N-terminal to the GGDEF domain that interacts with the EAL dimerization helix (α) of the other EAL monomer and maintains the protein in a locked conformation. We propose that local conformational changes in cRbdA upon GTP binding lead to a structure with the PAS domain and S-helix shifted away from the GGDEF-EAL domains, as suggested by small-angle X-ray scattering (SAXS) experiments. Domain reorientation should be facilitated by the presence of an α-helical lever (H-helix) that tethers the GGDEF and EAL regions, allowing the EAL domain to rearrange into an active dimeric conformation. Biofilm formation by bacterial pathogens increases resistance to antibiotics. RbdA positively regulates biofilm dispersal of The crystal structures of the cytoplasmic region of the RbdA protein presented here reveal that two evolutionarily conserved helices play an important role in regulating the activity of RbdA, with implications for other GGDEF-EAL dual domains that are abundant in the proteomes of several bacterial pathogens. Thus, this work may assist in the development of small molecules that promote bacterial biofilm dispersal.

PubMed: 29109186
DOI: 10.1128/JB.00515-17

Experimental method

X-RAY DIFFRACTION (2.28 Å)