BBB : Vol. 66 (2002) , No. 9 pp.1887-1896

Purification and Properties of an Extracellular Exoinulinase from Penicillium sp. Strain TN-88 and Sequence Analysis of the Encoding Gene

Satoshi MORIYAMA¹⁾, Hidetoshi AKIMOTO¹⁾, Norio SUETSUGU¹⁾, Soushi KAWASAKI¹⁾, Toyohiko NAKAMURA¹⁾ and Kazuyoshi OHTA¹⁾

1) Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, Miyazaki University

(Received March 4, 2002)
(Accepted April 23, 2002)

An exoinulinase, P-I, was purified from the culture filtrate of Penicillium sp. strain TN-88 grown on inulin. The enzyme was homogeneous as judged by SDS-polyacrylamide gel electrophoresis with an apparent M_r of 81 kDa. The purified enzyme had extremely high specific activity, 743 U/mg, toward inulin. Inulinase activity was optimal at pH 4.0 and 55°C. A genomic DNA and cDNAs encoding this protein were cloned and sequenced. The exoinulinase gene (inuD) was present as a single copy in the genome. An open reading frame of 2,106 bp was interrupted by a single intron of 56 bp, and encoded a 25-amino acid signal peptide and a 677-amino acid mature protein. The mature protein contained two Cys residues and eight potential N-linked glycosylation sites. The 5′-noncoding region had a putative CAAT box at position −239. Four distinct transcription start points were observed at positions −98 (A), −91 (A), −80 (A), and −76 (A) from the start codon. The exoinulinase gene inuD was located 860-bp upstream of the previously reported endoinulinase gene inuC in the opposite direction of transcription.

Key words:

exoinulinase; extracellular enzyme; gene cluster; inulin; Penicillium sp.

	To cite this article:
	Satoshi MORIYAMA, Hidetoshi AKIMOTO, Norio SUETSUGU, Soushi KAWASAKI, Toyohiko NAKAMURA and Kazuyoshi OHTA, “Purification and Properties of an Extracellular Exoinulinase from Penicillium sp. Strain TN-88 and Sequence Analysis of the Encoding Gene”, Biosci. Biotechnol. Biochem., Vol. 66, 1887-1896 (2002) .

	doi:10.1271/bbb.66.1887
	JOI JST.JSTAGE/bbb/66.1887