BBB : Vol. 64 (2000) , No. 12 pp.2614-2624

Cloning, Sequencing, and Expression of the Gene Encoding a Cell-bound Multi-domain Xylanase from Clostridium josui, and Characterization of the Translated Product

Jia-Xun FENG¹⁾, Shuichi KARITA²⁾, Emi FUJINO¹⁾, Tsuchiyoshi FUJINO³⁾, Tetsuya KIMURA¹⁾, Kazuo SAKKA¹⁾ and Kunio OHMIYA¹⁾

1) Faculty of Bioresources, Mie University
2) Center for Molecular Biology and Genetics, Mie University
3) Nagoya Seiraku Co. Ltd.

(Received June 12, 2000)
(Accepted July 27, 2000)

The nucleotide sequence of the Clostridium josui FERM P-9684 xyn10A gene, encoding a xylanase Xyn10A, consists of 3,150 bp and encodes 1,050 amino acids with a molecular weight of 115,564. Xyn10A 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 9 carbohydrate-binding module (CBM), and two S-layer homologous (SLH) domains. Immunological analysis indicated the presence of Xyn10A in the culture supernatant of C. josui FERM P-9684 and on the cell surface. The full-length Xyn10A expressed in a recombinant Escherichia coli strain bound to ball-milled cellulose (BMC) and the cell wall fragments of C. josui, indicating that both the CBM and the SLH domains are fully functional in the recombinant enzyme. An 85-kDa xylanase species derived from Xyn10A by partial proteolysis at the C-terminal side, most likely at the internal region of the CBM, retained the ability to bind to BMC. This observation suggests that the catalytic domain or the thermostabilizing domains are responsible for binding of the enzyme to BMC. Xyn10A-II, the 100-kDa derivative of Xyn10A, was purified from the recombinant E. coli strain and characterized. The enzyme was highly active toward xylan but not toward p-nitrophenyl-β-D-xylopyranoside, p-nitrophenyl-β-D-cellobioside, or carboxymethylcellulose.

Key words:

xylanase; Clostridium josui; carbohydrate-binding module; surface-layer homologous domain; thermostabilizing domain

	To cite this article:
	Jia-Xun FENG, Shuichi KARITA, Emi FUJINO, Tsuchiyoshi FUJINO, Tetsuya KIMURA, Kazuo SAKKA and Kunio OHMIYA, “Cloning, Sequencing, and Expression of the Gene Encoding a Cell-bound Multi-domain Xylanase from Clostridium josui, and Characterization of the Translated Product”, Biosci. Biotechnol. Biochem., Vol. 64, 2614-2624 (2000) .

	doi:10.1271/bbb.64.2614
	JOI JST.JSTAGE/bbb/64.2614