Structural Insights into the -Xylosidase from Trichoderma reesei Obtained by Synchrotron Small-Angle X-ray Sca
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- 作者：Adriana L. Rojas ; Hannes Fischer ; Elena V. Eneiskaya ; Anna A. Kulminskaya ; Konstantin A. Shabalin ; Kirill N. Neustroev ; Aldo F. Craievich ; Alexander M. Golubev ; and Igor Polikarpov
- 刊名：Biochemistry
- 出版年：2005
- 出版时间：November 29, 2005
- 年：2005
- 卷：44
- 期：47
- 页码：15578 - 15584
- 全文大小：1062K
- 年卷期：v.44,no.47(November 29, 2005)
- ISSN：1520-4995
文摘
The enzyme 
-xylosidase from Trichoderma reesei, a member of glycosil hydrolase family 3(GH3), is a glycoside hydrolase which acts at the glycosidic linkages of 1,4--xylooligosaccharides andthat also exhibits 
-L-arabinofuranosidase activity on 4-nitrophenyl -L-arabinofuranoside. In this work,we show that the enzyme forms monomers in solution and derive the low-resolution molecular envelopeof the -xylosidase from small-angle X-ray scattering (SAXS) data using the ab initio simulated annealingalgorithm. The radius of gyration and the maximum dimension of the -xylosidase are 30.3 ± 0.2 and 90± 5 Å, respectively. In contrast to the fold of the only two structurally characterized members of GH3,the barley -D-glucan exohydrolase and -hexosaminidase from Vibrio cholerae, which have respectivelytwo or one distinct domains, the shape of the -xylosidase indicates the presence of three distinct structuralmodules. Domain recognition algorithms were used to show that the C-terminal part of the amino acidsequence of the protein forms the third domain. Circular dichroism spectroscopy and secondary structureprediction programs demonstrate that this additional domain adopts a predominantly conformation.
-xylosidase from Trichoderma reesei, a member of glycosil hydrolase family 3(GH3), is a glycoside hydrolase which acts at the glycosidic linkages of 1,4--xylooligosaccharides andthat also exhibits -L-arabinofuranosidase activity on 4-nitrophenyl -L-arabinofuranoside. In this work,we show that the enzyme forms monomers in solution and derive the low-resolution molecular envelopeof the -xylosidase from small-angle X-ray scattering (SAXS) data using the ab initio simulated annealingalgorithm. The radius of gyration and the maximum dimension of the -xylosidase are 30.3 ± 0.2 and 90± 5 Å, respectively. In contrast to the fold of the only two structurally characterized members of GH3,the barley -D-glucan exohydrolase and -hexosaminidase from Vibrio cholerae, which have respectivelytwo or one distinct domains, the shape of the -xylosidase indicates the presence of three distinct structuralmodules. Domain recognition algorithms were used to show that the C-terminal part of the amino acidsequence of the protein forms the third domain. Circular dichroism spectroscopy and secondary structureprediction programs demonstrate that this additional domain adopts a predominantly conformation.