title: Genomic analysis of the protein secretion systems in Clostridium acetobutylicum ATCC 824.
abstract: Consistent information about protein secretion in Gram-positive bacteria is essentially restricted to the model organism Bacillus subtilis. Among genome-sequenced clostridia, Clostridium acetobutylicum has been the most extensively studied from a physiological point of view and is the organism for which the largest variety of molecular biology tools have been developed. Following in silico analyses, both secreted proteins and protein secretion systems were identified. The Tat (Twin arginine translocation; TC #2.A.64) pathway and ABC (ATP binding cassette) protein exporters (TC #3.A.1.) could not be identified, but the Sec (secretion) pathway (TC #3.A.5) appears to be used prevalently. Similarly, a flagella export apparatus (FEA; TC #3.A.6.), holins (TC #1.E.), and an ESAT-6/WXG100 (early secreted antigen target of 6 kDa/proteins with a WXG motif of approximately 100 residues) secretion system were identified. Here, we report for the first time the identification of a fimbrilin protein exporter (FPE; TC #3.A.14) and a Tad (tight adherence) export apparatus in C. acetobutylicum. This investigation highlights the potential use of this saprophytic bacterium in biotechnological and biomedical applications as well as a model organism for studying protein secretion in pathogenic Gram-positive bacteria.
authors.affiliation: The Institute for Biomedical Research (IBR), The University of Birmingham-The Medical School, Division of Immunity and Infection, Bacterial Pathogenesis and Genomics Unit, Edgbaston, Birmingham B15 2TT, UK. m.desvaux@bham.ac.uk
authors.forename: Mickaël
authors.initials: M
authors.lastname: Desvaux
authors.forename: Arshad
authors.initials: A
authors.lastname: Khan
authors.forename: Anthony
authors.initials: A
authors.lastname: Scott-Tucker
authors.forename: Roy R
authors.initials: RR
authors.lastname: Chaudhuri
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Pallen
authors.forename: Ian R
authors.initials: IR
authors.lastname: Henderson
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D044603:Cellulosomes / Q000502:physiology; D002794:Choline / Q000378:metabolism; D046969:Clostridium acetobutylicum / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D036781:Fimbriae Proteins / Q000502:physiology; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000502:physiology; D021382:Protein Sorting Signals / Q000235:genetics; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000502:physiology; D012276:Ricin / Q000235:genetics / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D021382:Protein Sorting Signals; C063055:fimbrillin; D036781:Fimbriae Proteins; D012276:Ricin; D002794:Choline