title: The chitinolytic machinery of Serratia marcescens--a model system for enzymatic degradation of recalcitrant polysaccharides.
abstract: The chitinolytic machinery of Serratia marcescens is one of the best known enzyme systems for the conversion of insoluble polysaccharides. This machinery includes four chitin-active enzymes: ChiC, an endo-acting non-processive chitinase; ChiA and ChiB, two processive chitinases moving along chitin chains in opposite directions; and CBP21, a surface-active CBM33-type lytic polysaccharide monooxygenase that introduces chain breaks by oxidative cleavage. Furthermore, an N-acetylhexosaminidase or chitobiase converts the oligomeric products from the other enzymes to monomeric N-acetylglucosamine. Here we discuss the catalytic mechanisms of these enzymes as well as the structural basis of each enzyme's specific role in the chitin degradation process. We also discuss how knowledge of this enzyme system may be extrapolated to other enzyme systems for conversion of insoluble polysaccharides, in particular conversion of cellulose by cellulases and GH61-type lytic polysaccharide monooxygenases.
authors: Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway.
authors: Gustav
authors: G
authors: Vaaje-Kolstad
authors: Svein J
authors: SJ
authors: Horn
authors: Morten
authors: M
authors: Sørlie
authors: Vincent G H
authors: VG
authors: Eijsink
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D055162:Biocatalysis; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002686:Chitin / Q000737:chemistry / Q000378:metabolism*; D002688:Chitinases / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000378:metabolism; D006868:Hydrolysis; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D008968:Molecular Conformation; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D012706:Serratia marcescens / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; D010940:Plant Proteins; D011134:Polysaccharides; C111062:chitin-binding protein 21, Serratia marcescens; D002686:Chitin; D006026:Glycoside Hydrolases; D002688:Chitinases