title: Biochemical characterization and gene expression of two endo-arabinanases from Penicillium chrysogenum 31B.
abstract: We previously described five arabinanolytic enzymes secreted by Penicillium chrysogenum 31B into the culture medium. Here, we describe a sixth such enzyme, termed AbnS1. Analysis of the reaction products of debranched arabinan revealed that AbnS1 cleaved the substrate in an endo manner. The optimum temperature of AbnS1 was 60°C, which was much higher than that of a cold-adapted endo-arabinanase (Abnc) produced by this strain. The abns1 cDNA gene encoding AbnS1 was isolated by in vitro cloning. The deduced amino acid sequence of AbnS1 had 70% identity with that of Abnc. Pfam analysis revealed a Glyco_hydro_43 domain at positions 28 to 318 of AbnS1. Semi-quantitative reverse transcription-polymerase chain reaction analysis indicated that the abns1 gene was constitutively expressed in P. chrysogenum 31B at a low level, although the expression was only slightly induced with arabinose and arabinan. In contrast, expression of the abnc gene encoding Abnc was strongly induced by arabinose, arabinitol, and arabinan. Using debranched arabinan as substrate, recombinant AbnS1 (rAbnS1) accumulated arabinobiose and arabinotriose as the major products. Recombinant Abnc (rAbnc) released mainly arabinotriose and lesser amounts of arabinose and arabinobiose than did rAbnS1. Branched arabinan was completely degraded to arabinose by the action of rAbnS1 or rAbnc in combination with α-L: -arabinofuranosidase.
authors: Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan. sakamoto@biochem.osakafu-u.ac.jp
authors: Tatsuji
authors: T
authors: Sakamoto
authors: Misako
authors: M
authors: Inui
authors: Kana
authors: K
authors: Yasui
authors: Sayaka
authors: S
authors: Tokuda
authors: Mika
authors: M
authors: Akiyoshi
authors: Yohei
authors: Y
authors: Kobori
authors: Tetsuko
authors: T
authors: Nakaniwa
authors: Toshiji
authors: T
authors: Tada
mesh_terms: D000595:Amino Acid Sequence; D001089:Arabinose / Q000378:metabolism; D003001:Cloning, Molecular; D003080:Cold Temperature; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D006026:Glycoside Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010408:Penicillium chrysogenum / Q000201:enzymology* / Q000235:genetics; D011134:Polysaccharides / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D011134:Polysaccharides; C030080:araban; D001089:Arabinose; C074451:Endo-arabinase; D006026:Glycoside Hydrolases