title: Multiple chitinases of an endophytic Serratia proteamaculans 568 generate chitin oligomers.
abstract: Serratia proteamaculans 568 genome revealed the presence of four family 18 chitinases (Sp ChiA, Sp ChiB, Sp ChiC, and Sp ChiD). Heterologous expression and characterization of Sp ChiA, Sp ChiB, and Sp ChiC showed that these enzymes were optimally active at pH 6.0-7.0, and 40°C. The three Sp chitinases displayed highest activity/binding to β-chitin and showed broad range of substrate specificities, and released dimer as major end product from oligomeric and polymeric substrates. Longer incubation was required for hydrolysis of trimer for the three Sp chitinases. The three Sp chitinases released up to tetramers from colloidal chitin substrate. Sp ChiA and Sp ChiB were processive chitinases, while Sp ChiC was a non-processive chitinase. Based on the known structures of ChiA and ChiB from S. marcescens, 3D models of Sp ChiA and Sp ChiB were generated.
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad-500 046, India.
authors.forename: Pallinti
authors.initials: P
authors.lastname: Purushotham
authors.forename: P V S R N
authors.initials: PV
authors.lastname: Sarma
authors.forename: Appa Rao
authors.initials: AR
authors.lastname: Podile
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D002686:Chitin / Q000378:metabolism*; D002688:Chitinases / Q000378:metabolism*; D003001:Cloning, Molecular; D003102:Colloids; D060026:Endophytes / Q000201:enzymology*; D004926:Escherichia coli / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D009844:Oligosaccharides / Q000378:metabolism*; D012705:Serratia / Q000201:enzymology*; D012995:Solubility; D013379:Substrate Specificity; D013696:Temperature; D013997:Time Factors
chemical_list: D001426:Bacterial Proteins; D003102:Colloids; D009844:Oligosaccharides; D002686:Chitin; D002688:Chitinases