title: General requirements for protein secretion by the F-like conjugation system R1.
abstract: Bacterial conjugation disseminates genes among bacteria via a process requiring direct cell contact. The cell envelope spanning secretion apparatus involved belongs to the type IV family of bacterial secretion systems, which transport protein as well as nucleoprotein substrates. This study aims to understand mechanisms leading to the initiation of type IV secretion using conjugative plasmid paradigm R1. We analyze the general requirements for plasmid encoded conjugation proteins and DNA sequence within the origin of transfer (oriT) for protein secretion activity using a Cre recombinase reporter system. We find that similar to conjugative plasmid DNA strand transfer, activation of the R1 system for protein secretion depends on binding interactions between the multimeric, ATP-binding coupling protein and the R1 relaxosome including an intact oriT. Evidence for DNA independent protein secretion was not found.
authors.affiliation: University of Graz, Institute of Molecular Biosciences, Humboldtstrasse 50/I, 8010 Graz, Austria.
authors.forename: Silvia
authors.initials: S
authors.lastname: Lang
authors.forename: Ellen L
authors.initials: EL
authors.lastname: Zechner
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D003227:Conjugation, Genetic; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D005144:F Factor / Q000235:genetics* / Q000378:metabolism*; D023061:Gene Order; D008565:Membrane Proteins / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics; D011815:R Factors / Q000235:genetics* / Q000378:metabolism*; D018741:Replication Origin
chemical_list: D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C064957:traD protein, E coli; C063238:traY protein, E coli; C074281:TraM protein, bacterial