3I5B

Crystal structure of the isolated GGDEF domain of WpsR from Pseudomonas aeruginosa

Summary for 3I5B

• Entry DOI: 10.2210/pdb3i5b/pdb
• Related: 3I5A 3I5C
• Descriptor: WspR response regulator, L(+)-TARTARIC ACID (3 entities in total)
• Functional Keywords: c-di-gmp, ggdef, signaling protein
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 2
• Total formula weight: 39291.92

Authors

Navarro, M.V.A.S.,De, N.,Sondermann, H. (deposition date: 2009-07-03, release date: 2009-08-18, Last modification date: 2024-02-21)

Primary citation

De, N.,Navarro, M.V.,Raghavan, R.V.,Sondermann, H.
Determinants for the activation and autoinhibition of the diguanylate cyclase response regulator WspR.
J.Mol.Biol., 393:619-633, 2009

PubMed Abstract: The bacterial second messenger bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) controls secretion, cell adhesion, and motility, leading to biofilm formation and increased cytotoxicity. Diguanylate cyclases containing GGDEF and phosphodiesterases containing EAL or HD-GYP domains have been identified as the enzymes controlling cellular c-di-GMP levels, yet less is known regarding the molecular mechanisms governing regulation and signaling specificity. We recently determined a product-inhibition pathway for the diguanylate cyclase response regulator WspR from Pseudomonas, a potent molecular switch that controls biofilm formation. In WspR, catalytic activity is modulated by a helical stalk motif that connects its phospho-receiver and GGDEF domains. The stalks facilitate the formation of distinct oligomeric states that contribute to both activation and autoinhibition. Here, we provide novel insights into the regulation of diguanylate cyclase activity in WspR based on the crystal structures of full-length WspR, the isolated GGDEF domain, and an artificially dimerized catalytic domain. The structures highlight that inhibition is achieved by restricting the mobility of rigid GGDEF domains, mediated by c-di-GMP binding to an inhibitory site at the GGDEF domain. Kinetic measurements and biochemical characterization corroborate a model in which the activation of WspR requires the formation of a tetrameric species. Tetramerization occurs spontaneously at high protein concentration or upon addition of the phosphomimetic compound beryllium fluoride. Our analyses elucidate common and WspR-specific mechanisms for the fine-tuning of diguanylate cyclase activity.

PubMed: 19695263
DOI: 10.1016/j.jmb.2009.08.030

Experimental method

X-RAY DIFFRACTION (2.043 Å)