A cel44C-man26A gene of endophytic Paenibacillus polymyxa GS01 has multi-glycosyl hydrolases in two catalytic domains.
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.
Cho
Kye Man
KM
Division of Applied Life Science, Gyeongsang National University, Chinju 660-701, South Korea.
Hong
Su Young
SY
Lee
Sun Mi
SM
Kim
Yong Hee
YH
Kahng
Goon Gjung
GG
Kim
Hoon
H
Yun
Han Dae
HD
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
D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D006026:Glycoside Hydrolases