title: Molecular characterization of type III secretion signals via analysis of synthetic N-terminal amino acid sequences.
abstract: Yersinia species utilize a type III secretion system to inject toxins, called Yops (Yersinia outer proteins), into eukaryotic cells. The N-termini of the Yops serve as type III secretion signals, but they do not share a consensus sequence. To simplify the analysis of type III secretion signals, we replaced amino acids 2-8 of the secreted protein YopE with all permutations (27 or 128) of synthetic serine/isoleucine sequences. The results demonstrate that amphipathic N-terminal sequences, containing four or five serine residues, have a much greater probability than hydrophobic or hydrophilic sequences to target YopE for secretion. Multiple linear regression analysis of the synthetic sequences was used to obtain a model for N-terminal secretion signals. The model accurately classifies the N-terminal sequences of native type III substrates as efficient secretion signals.
authors.affiliation: Department of Molecular Biology, Umeå University, Sweden. scottloyd23@hotmail.com
authors.forename: Scott A
authors.initials: SA
authors.lastname: Lloyd
authors.forename: Michael
authors.initials: M
authors.lastname: Sjöström
authors.forename: Sara
authors.initials: S
authors.lastname: Andersson
authors.forename: Hans
authors.initials: H
authors.lastname: Wolf-Watz
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism; D001665:Binding Sites; D014644:Genetic Variation; D016014:Linear Models; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism; D015007:Yersinia / Q000235:genetics* / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C081269:SycE protein, Yersinia; D015534:Trans-Activators; C063239:yopE protein, Yersinia