Molecular characterization of type III secretion signals via analysis of synthetic N-terminal amino acid sequences.
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.
Lloyd
Scott A
SA
Department of Molecular Biology, Umeå University, Sweden. scottloyd23@hotmail.com
Sjöström
Michael
M
Andersson
Sara
S
Wolf-Watz
Hans
H
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
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C081269:SycE protein, Yersinia; D015534:Trans-Activators; C063239:yopE protein, Yersinia