Structure and function of an acetyl xylan esterase (Est2A) from the rumen bacterium Butyrivibrio proteoclasticus.
Butyrivibrio proteoclasticus is a significant component of the microbial population of the rumen of dairy cattle. It is a xylan-degrading organism whose genome encodes a large number of open reading frames annotated as fiber-degrading enzymes. We have determined the three-dimensional structure of Est2A, an acetyl xylan esterase from B. proteoclasticus, at 2.1 Å resolution, along with the structure of an inactive mutant (H351A) at 2.0 Å resolution. The structure reveals two domains-a C-terminal SGNH domain and an N-terminal jelly-roll domain typical of CE2 family structures. The structures are accompanied by experimentally determined enzymatic parameters against two model substrates, para-nitrophenyl acetate and para-nitrophenyl butyrate. The suite of fiber-degrading enzymes produced by B. proteoclasticus provides a rich source of new enzymes of potential use in industrial settings.
Department of Biological Sciences, University of Waikato, Hamilton, New Zealand.
Marisa
M
Till
David C
DC
Goldstone
Graeme T
GT
Attwood
Christina D
CD
Moon
Willam J
WJ
Kelly
Vickery L
VL
Arcus
D000115:Acetylesterase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D045856:Butyrivibrio / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D002417:Cattle / Q000382:microbiology*; D002482:Cellulose / Q000378:metabolism; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011487:Protein Conformation
D002482:Cellulose; D000115:Acetylesterase; C081851:acetylxylan esterase