Coloning And Sequence Analysis Of β-mannanase Man78 Gene Belong To A New Glycoside Hydrolases Family From A. Tabescens

β-mannanase is a short name forβ-1,4-D-mannan mannanohydrolase.It is a kind of endohydro-enzyme that can hydrolyze t he substance wit hβ-1,4-D-indican-bond.It universally exits in the nature,including the inferior animals and legume plants,whereas microorganism is the main source forβ-mannanase.All mannanases belong to GHF 5 and GHF26.So,it is a new age for the research and usage of beta—mannanase.By inducing A.tabescens EJLY2098,and purifing the protein that A.tabescens EJLY2098 secreted,a single band on the SDS-PAGE was obtained,β-mannanase. Basing on this,the purifiedβ-mannanase was enzymolysis in gel,then analyzed the partial peptides in the protein.Three random peptides was obtained.Acording these sequences,we designed degenerate primers to amplify.A 1457bp DNA fragment was amplidied from A.tabescens EJLY2098 with the primers by degenerate PCR with the genome DNA as template.Gene specific primers derived from this partial sequence were used for the amplication of the 3'and 5'ends of this cDNA by RACE method,then splicing to a full-length cDNA sequence.Then the analysis including the ORF,homologous, primary structure,secondary structure,tertiary structure was made with the sequence.This work means that it has been finished that the seperation and the genes cloning of beta-mannanase Man45 and Man78 which produced by A.tabescens EJLY2098.The beta -mannanase Man 78 maybe a member of another new GHF but of GHF5 and GHF26.The penetrating research of the beta-mannanase Man78 is very important for the knowledge of beta-mannanases.