Dataset Information

Oligoribonuclease is the primary degradative enzyme for pGpG in Pseudomonas aeruginosa that is required for cyclic-di-GMP turnover.

ABSTRACT: The bacterial second messenger cyclic di-GMP (c-di-GMP) controls biofilm formation and other phenotypes relevant to pathogenesis. Cyclic-di-GMP is synthesized by diguanylate cyclases (DGCs). Phosphodiesterases (PDE-As) end signaling by linearizing c-di-GMP to 5'-phosphoguanylyl-(3',5')-guanosine (pGpG), which is then hydrolyzed to two GMP molecules by yet unidentified enzymes termed PDE-Bs. We show that pGpG inhibits a PDE-A from Pseudomonas aeruginosa. In a dual DGC and PDE-A reaction, excess pGpG extends the half-life of c-di-GMP, indicating that removal of pGpG is critical for c-di-GMP homeostasis. Thus, we sought to identify the PDE-B enzyme(s) responsible for pGpG degradation. A differential radial capillary action of ligand assay-based screen for pGpG binding proteins identified oligoribonuclease (Orn), an exoribonuclease that hydrolyzes two- to five-nucleotide-long RNAs. Purified Orn rapidly converts pGpG into GMP. To determine whether Orn is the primary enzyme responsible for degrading pGpG, we assayed cell lysates of WT and ?orn strains of P. aeruginosa PA14 for pGpG stability. The lysates from ?orn showed 25-fold decrease in pGpG hydrolysis. Complementation with WT, but not active site mutants, restored hydrolysis. Accumulation of pGpG in the ?orn strain could inhibit PDE-As, increasing c-di-GMP concentration. In support, we observed increased transcription from the c-di-GMP-regulated pel promoter. Additionally, the c-di-GMP-governed auto-aggregation and biofilm phenotypes were elevated in the ?orn strain in a pel-dependent manner. Finally, we directly detect elevated pGpG and c-di-GMP in the ?orn strain. Thus, we identified that Orn serves as the primary PDE-B enzyme that removes pGpG, which is necessary to complete the final step in the c-di-GMP degradation pathway.

SUBMITTER: Orr MW

PROVIDER: S-EPMC4568665 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature

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Oligoribonuclease is the primary degradative enzyme for pGpG in Pseudomonas aeruginosa that is required for cyclic-di-GMP turnover.

Orr Mona W MW Donaldson Gregory P GP Severin Geoffrey B GB Wang Jingxin J Sintim Herman O HO Waters Christopher M CM Lee Vincent T VT

Proceedings of the National Academy of Sciences of the United States of America 20150824 36

The bacterial second messenger cyclic di-GMP (c-di-GMP) controls biofilm formation and other phenotypes relevant to pathogenesis. Cyclic-di-GMP is synthesized by diguanylate cyclases (DGCs). Phosphodiesterases (PDE-As) end signaling by linearizing c-di-GMP to 5'-phosphoguanylyl-(3',5')-guanosine (pGpG), which is then hydrolyzed to two GMP molecules by yet unidentified enzymes termed PDE-Bs. We show that pGpG inhibits a PDE-A from Pseudomonas aeruginosa. In a dual DGC and PDE-A reaction, excess p ...[more]

PMID: 26305945

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Dataset Information

Oligoribonuclease is the primary degradative enzyme for pGpG in Pseudomonas aeruginosa that is required for cyclic-di-GMP turnover.

Publications

Oligoribonuclease is the primary degradative enzyme for pGpG in Pseudomonas aeruginosa that is required for cyclic-di-GMP turnover.

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