Cloning, purification and characterization of a thermostable amylosucrase from Deinococcus geothermalis.
Amylosucrase is a transglucosidase that catalyses the synthesis of an amylose-type polymer from sucrose, an abundant agro-resource. Here we describe a novel thermostable amylosucrase from the moderate thermophile Deinococcus geothermalis (DGAS). The dgas gene was cloned and expressed in Escherichia coli. The encoded enzyme was purified and characterized. DGAS displays a specific activity of 44 U mg(-1), an optimal temperature of 50 degrees C and a half-life of 26 h at 50 degrees C. Moreover, it produces an alpha-glucan at 50 degrees C, with an average degree of polymerization of 45 and a polymerization yield of 76%. DGAS is thus the most active and thermostable amylosucrase known to date.
Emond
Stéphane
S
Université de Toulouse; INSA, UPS, INP; LISBP, Toulouse, France.
Mondeil
Sophie
S
Jaziri
Kais
K
André
Isabelle
I
Monsan
Pierre
P
Remaud-Siméon
Magali
M
Potocki-Véronèse
Gabrielle
G
D000595:Amino Acid Sequence; D000688:Amylose / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D003001:Cloning, Molecular; D034301:Deinococcus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D004795:Enzyme Stability; D015870:Gene Expression; D005964:Glucosyltransferases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013696:Temperature
D001426:Bacterial Proteins; D000688:Amylose; D005964:Glucosyltransferases; C019700:amylosucrase