Enzymatic properties of two catalytic modules of Clostridium stercorarium pectate lyase Pel9A.
Clostridium stercorarium F-9 pectate lyase Pel9A is a modular enzyme composed of two hypothetical family-9 catalytic modules of the polysaccharide lyases, CM9-1 and CM9-2, in order from the N terminus. In this study, we constructed and characterized CM9-1 and CM9-2 polypeptides as rCM9-1 and rCM9-2 respectively. Both of them, like the full-length Pel9A, required the Ca2+ ion for their enzyme activities and showed high activity toward polygalacturonic acid but lower activity toward pectin. The specific activity of rCM9-2 was three times higher than that of rCM9-1 and rCM9-2 by itself efficiently catalyzed the depolymerization reaction of polygalacturonic acid into monosaccharide as the major product. It was found that rCM9-1 and rCM9-2 adsorbed to polygalacturonic acid and pectin on native affinity PAGE analysis, suggesting that they contain an independent carbohydrate-binding module separable from a catalytic module or consist of a catalytic module with a binding affinity for pectic substrates.
Faculty of Bioresources, Mie University, Japan.
Si Si Hla
Takuma
T
Kikuta
Makiko
M
Sakka
Tetsuya
T
Kimura
Kazuo
K
Sakka
D002118:Calcium / Q000737:chemistry / Q000494:pharmacology; D002384:Catalysis; D002413:Cations, Divalent / Q000737:chemistry; D003013:Clostridium / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D008745:Methylation; D010368:Pectins / Q000378:metabolism; D011133:Polysaccharide-Lyases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012995:Solubility; D013379:Substrate Specificity
D002413:Cations, Divalent; D011994:Recombinant Proteins; D010368:Pectins; D011133:Polysaccharide-Lyases; C023911:pectate lyase; D002118:Calcium; C003181:polygalacturonic acid