title: Archaeal homolog of bacterial type IV prepilin signal peptidases with broad substrate specificity.
abstract: A large number of secretory proteins in the thermoacidophile Sulfolobus solfataricus are synthesized as a precursor with an unusual leader peptide that resembles bacterial type IV prepilin signal sequences. This set of proteins includes the flagellin subunit but also various solute binding proteins. Here we describe the identification of the S. solfataricus homolog of bacterial type IV prepilin peptidases, termed PibD. PibD is an integral membrane protein that is phylogenetically related to the bacterial enzymes. When heterologously expressed in Escherichia coli, PibD is capable of processing both the flagellin and glucose-binding protein (GlcS) precursors. Site-directed mutagenesis of the GlcS signal peptide shows that the substrate specificity of PibD is consistent with the variations found in proteins with type IV prepilin-like signal sequences of S. solfataricus. We conclude that PibD is responsible for the processing of these secretory proteins in S. solfataricus.
authors.affiliation: Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9751 NN Haren, The Netherlands.
authors.forename: Sonja-Verena
authors.initials: SV
authors.lastname: Albers
authors.forename: Zalán
authors.initials: Z
authors.lastname: Szabó
authors.forename: Arnold J M
authors.initials: AJ
authors.lastname: Driessen
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010450:Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011498:Protein Precursors / Q000378:metabolism; D021382:Protein Sorting Signals / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D016944:Sulfolobus / Q000201:enzymology* / Q000235:genetics
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D008565:Membrane Proteins; D011498:Protein Precursors; D021382:Protein Sorting Signals; D010450:Endopeptidases; C074273:type IV prepilin peptidase