title: Structural and functional characterization of a phosphatase domain within yeast general transcription factor IIIC.
abstract: Saccharomyces cerevisiae τ55, a subunit of the RNA polymerase III-specific general transcription factor TFIIIC, comprises an N-terminal histidine phosphatase domain (τ55-HPD) whose catalytic activity and cellular function is poorly understood. We solved the crystal structures of τ55-HPD and its closely related paralogue Huf and used in silico docking methods to identify phosphoserine- and phosphotyrosine-containing peptides as possible substrates that were subsequently validated using in vitro phosphatase assays. A comparative phosphoproteomic study identified additional phosphopeptides as possible targets that show the involvement of these two phosphatases in the regulation of a variety of cellular functions. Our results identify τ55-HPD and Huf as bona fide protein phosphatases, characterize their substrate specificities, and provide a small set of regulated phosphosite targets in vivo.
authors.affiliation: Structural and Computational Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
authors.forename: Nicholas M I
authors.initials: NM
authors.lastname: Taylor
authors.forename: Sebastian
authors.initials: S
authors.lastname: Glatt
authors.forename: Marco L
authors.initials: ML
authors.lastname: Hennrich
authors.forename: Gudrun
authors.initials: G
authors.lastname: von Scheven
authors.forename: Helga
authors.initials: H
authors.lastname: Grötsch
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-Tornero
authors.forename: Vladimir
authors.initials: V
authors.lastname: Rybin
authors.forename: Anne-Claude
authors.initials: AC
authors.lastname: Gavin
authors.forename: Peter
authors.initials: P
authors.lastname: Kolb
authors.forename: Christoph W
authors.initials: CW
authors.lastname: Müller
mesh_terms: D018360:Crystallography, X-Ray; D062105:Molecular Docking Simulation; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry* / Q000235:genetics; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics; D019474:Transcription Factors, TFIII / Q000737:chemistry* / Q000235:genetics; D000098832:Transcription Factor TFIIIC
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D019474:Transcription Factors, TFIII; C410600:YNL108C protein, S cerevisiae; D000098832:Transcription Factor TFIIIC; D010744:Phosphoric Monoester Hydrolases
keywords: Enzyme Structure; Histidine Phosphatase Family; Mass Spectrometry (MS); Metabolism; Molecular Docking; Phosphoproteomics; Protein Phosphatase; RNA Polymerase III; Transcription Regulation; X-ray Crystallography