title: Genetic dissection of a motility-associated c-di-GMP signalling protein of Pseudomonas putida.
abstract: Lack of the Pseudomonas putida PP2258 protein or its overexpression results in defective motility on solid media. The PP2258 protein is tripartite, possessing a PAS domain linked to two domains associated with turnover of c-di-GMP - a cyclic nucleotide that controls the switch between motile and sessile lifestyles. The second messenger c-di-GMP is produced by diguanylate cyclases and degraded by phosphodiesterases containing GGDEF and EAL or HD-GYP domains respectively. It is common for enzymes involved in c-di-GMP signalling to contain two domains with potentially opposing c-di-GMP turnover activities; however, usually one is degenerate and has been adopted to serve regulatory functions. Only a few proteins have previously been found to have dual enzymatic activities - being capable of both synthesizing and hydrolysing c-di-GMP. Here, using truncated and mutant derivatives of PP2258, we show that despite a lack of complete consensus in either the GGDEF or EAL motifs, the two c-di-GMP turnover domains can function independently of each other, and that the diguanylate cyclase activity is regulated by an inhibitory I-site within its GGDEF domain. Thus, motility-associated PP2258 can be added to the short list of bifunctional c-di-GMP signalling proteins.
authors.affiliation: Department of Molecular Biology, Umeå University, SE-90187, Umeå, Sweden.
authors.forename: Sofia
authors.initials: S
authors.lastname: Österberg
authors.forename: Anna
authors.initials: A
authors.lastname: Åberg
authors.forename: M Karina
authors.initials: MK
authors.lastname: Herrera Seitz
authors.forename: Magnus
authors.initials: M
authors.lastname: Wolf-Watz
authors.forename: Victoria
authors.initials: V
authors.lastname: Shingler
mesh_terms: D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008124:Locomotion; D008958:Models, Molecular; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D016958:Pseudomonas putida / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D017384:Sequence Deletion; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D050505:Mutant Proteins; C062025:bis(3',5')-cyclic diguanylic acid; D006152:Cyclic GMP