Increased xylanase production in Streptomyces lividans after replacement of the signal peptide: dependence on box and inverted repeat sequence.
The signal peptide of the xylanase A gene of Streptomyces lividans was replaced by the signal sequence of the cellulase A preceded by a 57 nucleotides (nt) upstream sequence. This latter contains a 5 nt inverted repeat (5'-TGGGAACGCTCCCA). The 3'-end of the inverted repeat contains a 5 nt box (TCCCA), which is complementary to the 16S rRNA of S. lividans. The effects on the production of xylanase resulting from deletions in the inverted repeat and from variations in the length of the box are shown. Removal of the inverted repeat and box decreased the xylanase production by 75%. Increasing the complementarity of the box with the 16S rRNA to 17 nt decreased the production by 90%. A reduction in the length of the inverted repeat, and consequently in the box, from 5 to 4 nt decreased the production by 40%. Preserving the 4 nt inverted repeat but lengthening the box from 5 to 6 nt increased the production by 1.5-fold. Finally, removing the inverted repeat but introducing an 8 nt box increased the xylanase production by 1.9-fold which then averaged 2.3 g/l of xylanase. The most efficient boxes contained 6-8 nt and were located between 14 and 19 nt downstream from the first initiation codon.
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Centre de Recherche en Microbiologie et Biotechnologie, INRS-Institut Armand-Frappier, Université du Québec, 531 Boul. des Prairies, P.O. Box 100, Ville de Laval, Que., Canada.
Dupont
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Morosoli
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D002999:Clone Cells; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D014176:Protein Biosynthesis; D021382:Protein Sorting Signals / Q000235:genetics / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D015854:Up-Regulation; D043325:Xylan Endo-1,3-beta-Xylosidase; D014995:Xylosidases / Q000096:biosynthesis* / Q000235:genetics
D021382:Protein Sorting Signals; D014995:Xylosidases; D043325:Xylan Endo-1,3-beta-Xylosidase