title: [Does spiralin has a cleavable N-terminal signal sequence?].
abstract: The amino acid sequence of spiralin deduced from the nucleotide sequence of its gene was fictitiously shortened by 1 to 50 residues from each terminus and the compositions of both series of theoretical polypeptides were calculated. The two series of compositions thus obtained were compared to that of the purified protein, with the use of the Marchalonis and Weltman index (S delta Q). The results of this analysis, which permits the difficulty resulting from the blocking of the N-terminal amino acid to be overcome, show that spiralin is probably synthesized as a 241-residue precursor containing an N-terminal signal sequence cleaved close to cysteine-24. Since spiralin is acylated and since the sequence Val-Val-Ala-Cys24 shares some similarity with the consensus sequence of bacterial lipoprotein modification/processing site, the hypothesis of a cleavage just before cysteine-24 seems plausible.
authors.affiliation: Laboratoire d'Immunochimie des Membranes bactériennes, Université de Rennes-I, C.N.R.S.-U.R.A. n. 256.
authors.forename: M
authors.initials: M
authors.lastname: Le Hénaff
authors.forename: C
authors.initials: C
authors.lastname: Brenner
authors.forename: C
authors.initials: C
authors.lastname: Fontenelle
authors.forename: C
authors.initials: C
authors.lastname: Delamarche
authors.forename: H
authors.initials: H
authors.lastname: Wróblewski
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D010443:Peptide Chain Termination, Translational; D021382:Protein Sorting Signals / Q000737:chemistry*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D021382:Protein Sorting Signals; C028588:spiralin
vernacular_title: La spiraline possède-t-elle une séquence signal N-terminale clivable?