title: The RicAFT (YmcA-YlbF-YaaT) complex carries two [4Fe-4S]2+clusters and may respond to redox changes.
abstract: During times of environmental insult, Bacillus subtilis undergoes developmental changes leading to biofilm formation, sporulation and competence. Each of these states is regulated in part by the phosphorylated form of the master response regulator Spo0A (Spo0A∼P). The phosphorylation state of Spo0A is controlled by a multi-component phosphorelay. RicA, RicF and RicT (previously YmcA, YlbF and YaaT) have been shown to be important regulatory proteins for multiple developmental fates. These proteins directly interact and form a stable complex, which has been proposed to accelerate the phosphorelay. Indeed, this complex is sufficient to stimulate the rate of phosphotransfer amongst the phosphorelay proteins in vitro. In this study, we demonstrate that two [4Fe-4S]2+clusters can be assembled on the complex. As with other iron-sulfur cluster-binding proteins, the complex was also found to bind FAD, hinting that these cofactors may be involved in sensing the cellular redox state. This work provides the first comprehensive characterization of an iron-sulfur protein complex that regulates Spo0A∼P levels. Phylogenetic and genetic evidence suggests that the complex plays a broader role beyond stimulation of the phosphorelay.
authors.affiliation: Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.
authors.forename: Andrew W
authors.identifier: http://orcid.org/0000-0001-6412-7201
authors.initials: AW
authors.lastname: Tanner
authors.affiliation: Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.|Public Health Research Institute Center, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.
authors.forename: Valerie J
authors.initials: VJ
authors.lastname: Carabetta
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Martinie
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA.
authors.forename: Ameya A
authors.initials: AA
authors.lastname: Mashruwala
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Boyd
authors.affiliation: Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.|Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
authors.forename: Carsten
authors.initials: C
authors.lastname: Krebs
authors.affiliation: Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.|Public Health Research Institute Center, New Jersey Medical School, Rutgers University, Newark, NJ, 07103, USA.
authors.forename: David
authors.identifier: http://orcid.org/0000-0001-9713-6120
authors.initials: D
authors.lastname: Dubnau
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism; D005182:Flavin-Adenine Dinucleotide / Q000031:analogs & derivatives / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D010084:Oxidation-Reduction; D010766:Phosphorylation; D010802:Phylogeny; D013171:Spores, Bacterial; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; C080950:Spo0A protein, Bacillus subtilis; D014157:Transcription Factors; D005182:Flavin-Adenine Dinucleotide; C058805:1,5-dihydro-FAD; D003545:Cysteine