Molecular characterization and expression of microbial inulinase genes.
Many genes encoding exo- and endo-inulinases from bacteria, yeasts and filamentous fungi have been cloned and characterized. All the inulinases have several conserved motifs, such as WMND(E)PNGL, RDP, EC(V)P, SVEVF, Q and FS(T), which play an important role in inulinase catalysis and substrate binding. However, the exo-inulinases produced by yeasts has no conserved motif SVEVF and the yeasts do not produce any endo-inulinase. Exo- and endo-inulinases found in different microorganisms cluster separately at distant positions from each other. Most of the cloned inulinase genes have been expressed in Yarrowia lipolytica, Saccharomyces cerevisiae, Pichia pastoris, Klyuveromyces lactis and Escherichia coli, respectively. The recombinant inulinases produced and the engineered hosts using the cloned inulinase genes have many potential applications. Expression of most of the inulinase genes is repressed by glucose and fructose and induced by inulin and sucrose. However, the detailed mechanisms of the repression and induction are still unknown.
Unesco Chinese Center of Marine Biotechnology, Ocean University of China, Yushan Road, Qingdao, China.
Guang-Lei
GL
Liu
Zhe
Z
Chi
Zhen-Ming
ZM
Chi
D001419:Bacteria / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005658:Fungi / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D015870:Gene Expression; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D005656:Fungal Proteins; D006026:Glycoside Hydrolases; C023086:inulinase