Cloning, sequencing, and expression of the gene encoding the Clostridium stercorarium xylanase C in Escherichia coli. |
| |
Authors: | M K Ali M Fukumura K Sakano S Karita T Kimura K Sakka K Ohmiya |
| |
Institution: | Department of Bioscience, Faculty of Bioresources, Mie University, Tsu, Japan. |
| |
Abstract: | The nucleotide sequence of the Clostridium stercorarium F-9 xynC gene, encoding a xylanase XynC, consists of 3,093 bp and encodes a 1,031-amino acids with a molecular weight of 115,322. XynC is a multidomain enzyme composed of an N-terminal signal peptide and six domains in the following order: two thermostabilizing domains, a family 10 xylanase domain, a family IX cellulose-binding domain, and two S-layer homologous domains. Immunological analysis indicated the presence of XynC in the culture supernatant of C. stercorarium F-9 and in the cells, most likely on the cell surface. XynC purified from a recombinant E. coli was highly active toward xylan and slightly active toward p-nitrophenyl-beta-D-xylopyranoside, p-nitrophenyl-beta-D-cellobioside, p-nitrophenyl-beta-D-glucopyranoside, and carboxymethylcellulose. XynC hydrolyzed xylan and xylooligosaccharides larger than xylotriose to produce xylose and xylobiose. This enzyme was optimally active at 85 degrees C and was stable up to 75 degrees C at pH 5.0 and over the pH range of 4 to 7 at 25 degrees C. |
| |
Keywords: | |
|
|