Nucleotide sequence and deletion analysis of the xylanase gene (xynZ) of Clostridium thermocellum.

摘要: The nucleotide sequence of the xynZ gene, encoding extracellular xylanase Z Clostridium thermocellum, was determined. putative gene 2,511 base pairs long and encoded a polypeptide 837 amino acids. A region 60 acids containing duplicated segment 24 found between residues 429 488 Z. This strongly similar to conserved domain at carboxy-terminal ends C. thermocellum endoglucanases A, B, D. Deletions removing up 508 codons from 59 end did not affect activity polypeptide, showing that active site located in C-terminal half protein involved catalysis. Expression Escherichia coli increased 220-fold by fusing fragments 39 with start lacZ present pUC19. An internal translational initiation which efficiently recognized E. tentatively identified 470 downstream actual codon. Images