title: A cel44C-man26A gene of endophytic Paenibacillus polymyxa GS01 has multi-glycosyl hydrolases in two catalytic domains.
abstract: A bacterial strain Paenibacillus polymyxa GS01 was isolated from the interior of the roots of Korean cultivars of ginseng (Panax ginseng C. A. Meyer). The cel44C-man26A gene was cloned from this endophytic strain. This 4,056-bp gene encodes for a 1,352-aa protein which, based on BLAST search homologies, contains a glycosyl hydrolase family 44 (GH44) catalytic domain, a fibronectin domain type 3, a glycosyl hydrolase family 26 (GH26) catalytic domain, and a cellulose-binding module type 3. The multifunctional enzyme domain GH44 possesses cellulase, xylanase, and lichenase activities, while the enzyme domain GH26 possesses mannanase activity. The Cel44C enzyme expressed in and purified from Escherichia coli has an optimum pH of 7.0 for cellulase and lichenase activities, but is at an optimum pH of 5.0 for xylanase and mannanase activities. The optimum temperature for enzymatic activity was 50 degrees C for all substrates. No detectable enzymatic activity was detected for the Cel44C-Man26A mutants E91A and E222A. These results suggest that the amino acid residues Glu(91) and Glu(222) may play an important role in the glycosyl hydrolases activity of Cel44C-Man26A.
authors.affiliation: Division of Applied Life Science, Gyeongsang National University, Chinju 660-701, South Korea.
authors.forename: Kye Man
authors.initials: KM
authors.lastname: Cho
authors.forename: Su Young
authors.initials: SY
authors.lastname: Hong
authors.forename: Sun Mi
authors.initials: SM
authors.lastname: Lee
authors.forename: Yong Hee
authors.initials: YH
authors.lastname: Kim
authors.forename: Goon Gjung
authors.initials: GG
authors.lastname: Kahng
authors.forename: Hoon
authors.initials: H
authors.lastname: Kim
authors.forename: Han Dae
authors.initials: HD
authors.lastname: Yun
mesh_terms: D000595:Amino Acid Sequence; D001407:Bacillus / Q000145:classification / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D020134:Catalytic Domain; D003001:Cloning, Molecular; D004275:DNA, Ribosomal / Q000235:genetics; D005798:Genes, Bacterial; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D005894:Panax / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D006026:Glycoside Hydrolases