CELL 46 |
| A gene encoding a novel a-L-arabinofuranosidase termed deAFc (1581 bp) was isolated from a culture seeded with a compost starter mixed bacterial population. The gene was cloned into E. coli with a C-terminal His-tag and its recombinant product characterized. Sequence analysis determined that the enzyme is a glycoside hydrolase (GH) family 43 member. The enzyme was monomeric under the size exclusion chromatography conditions employed and exhibits an apparent molecular weight of 57.9Kda. The Michaelis constant (Km) values were between 0.251 mM and 0.960 mM, and Kcat values between 0.13 sec -1 and 1.22 sec -1 on artificial glycoside substrates . The purified enzyme was stable up to 45 °C, had an activity temperature optimum of 47 °C, and a pH profile that was invariant between pH 5 and pH 8.5. deAFc released xylose only when incubated with synthetic xylopyranoside substrates. It released arabinose from synthethic and from natural substrates like arabinoxylan and branched arabinan. |
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Poster Session
4:00 PM-6:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Division of Cellulose & Renewable Materials |