Conserved serine‐rich sequences in xylanase and cellulase from Pseudomonas fluorescens subspecies cellulosa: internal signal sequence and unusual protein processing

Summary The complete nucleotide sequence of the xynA gene coding for a xylanase (XYLA) expressed by Pseudomonas fluorescens subspecies cellulosa, has been determined. The structural gene consists of an open reading frame of 1833 bp followed by a TAA stop codon. Confirmation of the nucleotide sequenc...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Molecular microbiology 1989-09, Vol.3 (9), p.1211-1219
Hauptverfasser: Hall, J., Hazlewood, G. P., Huskisson, N. S., Durrant, A. J., Gilbert, H. J.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Summary The complete nucleotide sequence of the xynA gene coding for a xylanase (XYLA) expressed by Pseudomonas fluorescens subspecies cellulosa, has been determined. The structural gene consists of an open reading frame of 1833 bp followed by a TAA stop codon. Confirmation of the nucleotide sequence was obtained by comparing the predicted amino acid sequence with that derived by N‐terminal analysis of purified forms of the xylanase. The signal peptide present at the N terminus of mature XYLA closely resembles signal peptides of other secreted proteins. Truncated forms of the xylanase gene, in which the sequence encoding the N‐terminal signal peptide had been deleted, still expressed an enzyme which was secreted in Escherichia coli. XYLA contains domains which are homologous to an endoglucanase expressed by the same organism. These structures include serine‐rich sequences. Bal31 deletions of xynA revealed the extent to which these conserved sequences, in XYLA, were essential for xylanase activity. Downstream of the TAA stop codon is a G + C‐rich region of dyad symmetry (δG = 24kcal) characteristic of E. coli Rho‐independent transcription terminators.
ISSN:0950-382X
1365-2958
DOI:10.1111/j.1365-2958.1989.tb00271.x