title: Identification and molecular characterization of a cyclic-di-GMP effector protein, PlzA (BB0733): additional evidence for the existence of a functional cyclic-di-GMP regulatory network in the Lyme disease spirochete, Borrelia burgdorferi.
abstract: The Borrelia burgdorferi Rrp1 protein is a diguanylate cyclase that controls a regulon consisting of approximately 10% of the total genome. Because Rrp1 lacks a DNA-binding domain, its regulatory capability is most likely mediated through the production of bis-(3'-5')-cyclic dimeric GMP (c-di-GMP). C-di-GMP binds to and activates the regulatory activity of proteins that harbor a PilZ domain. The occurrence of a PilZ domain within a protein is not in and of itself sufficient to convey c-di-GMP binding, as other structural aspects of the protein are important in the interaction. In this study, we have assessed the expression and c-di-GMP binding ability of the sole PilZ domain-containing protein of B. burgdorferi B31, PlzA. PlzA was determined to be upregulated by tick feeding and to be expressed during mammalian infection. The gene is highly conserved and present in all Borrelia species. Analyses of recombinant PlzA demonstrated its ability to bind c-di-GMP and site-directed mutagenesis revealed that this interaction is highly specific and dependent on Arg residues contained within the PilZ domain. In summary, this study is the first to identify a c-di-GMP effector molecule in a spirochete and provides additional evidence for the existence of a complete c-di-GMP regulatory network in the Lyme disease spirochete, B. burgdorferi.
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Freedman
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Rogers
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Kostick
authors.forename: Hongming
authors.initials: H
authors.lastname: Zhang
authors.forename: Radha
authors.initials: R
authors.lastname: Iyer
authors.forename: Ira
authors.initials: I
authors.lastname: Schwartz
authors.forename: Richard T
authors.initials: RT
authors.lastname: Marconi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D025065:Borrelia burgdorferi / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016000:Cluster Analysis; D017124:Conserved Sequence; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000378:metabolism; D018628:Gene Dosage; D015964:Gene Expression Regulation, Bacterial; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D050505:Mutant Proteins; C062025:bis(3',5')-cyclic diguanylic acid; D006152:Cyclic GMP