Insights into the GTP‐dependent allosteric control of c‐di‐GMP hydrolysis from the crystal structure of PA0575 protein from Pseudomonas aeruginosa. (7th September 2018)

• Record Type: Journal Article
• Authors: Mantoni, Federico; Paiardini, Alessandro; Brunotti, Paolo; D'Angelo, Cecilia; Cervoni, Laura; Paone, Alessio; Cappellacci, Loredana; Petrelli, Riccardo; Ricciutelli, Massimo; Leoni, Livia; Rampioni, Giordano; Arcovito, Alessandro; Rinaldo, Serena; Cutruzzolà, Francesca; Giardina, Giorgio
• Is Part Of: FEBS journal. Volume 285:Number 20(2018)
• Page Start: 3815
• Page End: 3834
• Publication Date: 2018-09-07
• Subjects: c‐di‐GMP -- GTP -- hybrid protein -- phosphodiesterase -- RmcA; Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pathology, Molecular -- Periodicals; 572
• DOI: 10.1111/febs.14634
• Languages: English
• ISSNs: 1742-464X

Abstract

Abstract : Bis‐(3′‑5′)‐cyclic diguanylic acid (c‑di‑GMP) belongs to the class of cyclic dinucleotides, key carriers of cellular information in prokaryotic and eukaryotic signal transduction pathways. In bacteria, the intracellular levels of c‐di‐GMP and their complex physiological outputs are dynamically regulated by environmental and internal stimuli, which control the antagonistic activities of diguanylate cyclases (DGCs) and c‐di‐GMP specific phosphodiesterases (PDEs). Allostery is one of the major modulators of the c‐di‐GMP‐dependent response. Both the c‐di‐GMP molecule and the proteins interacting with this second messenger are characterized by an extraordinary structural plasticity, which has to be taken into account when defining and possibly predicting c‐di‐GMP‐related processes. Here, we report a structure‐function relationship study on the catalytic portion of the PA0575 protein from Pseudomonas aeruginosa, bearing both putative DGC and PDE domains. The kinetic and structural studies indicate that the GGDEF‐EAL portion is a GTP‐dependent PDE. Moreover, the crystal structure confirms the high degree of conformational flexibility of this module. We combined structural analysis and protein engineering studies to propose the possible molecular mechanism guiding the nucleotide‐dependent allosteric control of catalysis; we propose that the role exerted by GTP via the GGDEF domain is to allow the two EAL domains to form a dimer, the species competent to enter PDE catalysis. Abstract : The catalytic portion (GGDEF‐EAL domains in tandem) of the Pseudomonas aeruginosa PA0575 protein (RmcA) is a phosphodiesterase (PDE) allosterically controlled by GTP. The crystal structure confirms the large plasticity of this motif; we propose that this feature allows the two EAL domains to form a dimer, the catalytically competent species, upon GTP binding to the GGDEF module.