Crystal structure and substrate specificity modification of acetyl xylan esterase from Aspergillus luchuensis

Dai Komiya, Akane Hori, Takuya Ishida, Kiyohiko Igarashi, Masahiro Samejima, Takuya Koseki, Shinya Fushinobu

Research output: Contribution to journalArticleScientificpeer-review

5 Citations (Scopus)

Abstract

Acetyl xylan esterase (AXE) catalyzes the hydrolysis of the acetyl bonds present in plant cell wall polysaccharides. Here, we determined the crystal structure of AXE from Aspergillus luchuensis (AlAXEA), providing the three-dimensional structure of an enzyme in the Esterase_phb family. AlAXEA shares its core α/β-hydrolase fold structure with esterases in other families, but it has an extended central β-sheet at both its ends and an extra loop. Structural comparison with a ferulic acid esterase (FAE) from Aspergillus niger indicated that AlAXEA has a conserved catalytic machinery: a catalytic triad (Ser119, His259, and Asp202) and an oxyanion hole (Cys40 and Ser120). Near the catalytic triad of AlAXEA, two aromatic residues (Tyr39 and Trp160) form small pockets at both sides. Homology models of fungal FAEs in the same Esterase_phb family have wide pockets at the corresponding sites because they have residues with smaller side chains (Pro, Ser, and Gly). Mutants with sitedirected mutations at Tyr39 showed a substrate specificity similar to that of the wild-type enzyme, whereas those with mutations at Trp160 acquired an expanded substrate specificity. Interestingly, the Trp160 mutants acquired weak but significant type B-like FAE activity. Moreover, the engineered enzymes exhibited ferulic acid-releasing activity from wheat arabinoxylan.

Original languageEnglish
Article numbere01251-17
JournalApplied and Environmental Microbiology
Volume83
Issue number20
Early online date2017
DOIs
Publication statusPublished - 2017
MoE publication typeA1 Journal article-refereed

Fingerprint

acetylxylan esterase
xylan
Esterases
Aspergillus
substrate specificity
Substrate Specificity
crystal structure
esterases
ferulic acid
enzyme
substrate
mutation
acid
Enzymes
Mutation
Aspergillus niger
Plant Cells
Hydrolases
homology
polysaccharide

Keywords

  • aspergillus luchuensis
  • carboxylesterase
  • catalytic triad
  • enzyme structure
  • ESTHER database
  • X-ray crystallography
  • a/ß-hydrolase fold

Cite this

Komiya, Dai ; Hori, Akane ; Ishida, Takuya ; Igarashi, Kiyohiko ; Samejima, Masahiro ; Koseki, Takuya ; Fushinobu, Shinya. / Crystal structure and substrate specificity modification of acetyl xylan esterase from Aspergillus luchuensis. In: Applied and Environmental Microbiology. 2017 ; Vol. 83, No. 20.
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title = "Crystal structure and substrate specificity modification of acetyl xylan esterase from Aspergillus luchuensis",
abstract = "Acetyl xylan esterase (AXE) catalyzes the hydrolysis of the acetyl bonds present in plant cell wall polysaccharides. Here, we determined the crystal structure of AXE from Aspergillus luchuensis (AlAXEA), providing the three-dimensional structure of an enzyme in the Esterase_phb family. AlAXEA shares its core α/β-hydrolase fold structure with esterases in other families, but it has an extended central β-sheet at both its ends and an extra loop. Structural comparison with a ferulic acid esterase (FAE) from Aspergillus niger indicated that AlAXEA has a conserved catalytic machinery: a catalytic triad (Ser119, His259, and Asp202) and an oxyanion hole (Cys40 and Ser120). Near the catalytic triad of AlAXEA, two aromatic residues (Tyr39 and Trp160) form small pockets at both sides. Homology models of fungal FAEs in the same Esterase_phb family have wide pockets at the corresponding sites because they have residues with smaller side chains (Pro, Ser, and Gly). Mutants with sitedirected mutations at Tyr39 showed a substrate specificity similar to that of the wild-type enzyme, whereas those with mutations at Trp160 acquired an expanded substrate specificity. Interestingly, the Trp160 mutants acquired weak but significant type B-like FAE activity. Moreover, the engineered enzymes exhibited ferulic acid-releasing activity from wheat arabinoxylan.",
keywords = "aspergillus luchuensis, carboxylesterase, catalytic triad, enzyme structure, ESTHER database, X-ray crystallography, a/{\ss}-hydrolase fold",
author = "Dai Komiya and Akane Hori and Takuya Ishida and Kiyohiko Igarashi and Masahiro Samejima and Takuya Koseki and Shinya Fushinobu",
year = "2017",
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language = "English",
volume = "83",
journal = "Applied and Environmental Microbiology",
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Crystal structure and substrate specificity modification of acetyl xylan esterase from Aspergillus luchuensis. / Komiya, Dai; Hori, Akane; Ishida, Takuya; Igarashi, Kiyohiko; Samejima, Masahiro; Koseki, Takuya; Fushinobu, Shinya.

In: Applied and Environmental Microbiology, Vol. 83, No. 20, e01251-17, 2017.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Crystal structure and substrate specificity modification of acetyl xylan esterase from Aspergillus luchuensis

AU - Komiya, Dai

AU - Hori, Akane

AU - Ishida, Takuya

AU - Igarashi, Kiyohiko

AU - Samejima, Masahiro

AU - Koseki, Takuya

AU - Fushinobu, Shinya

PY - 2017

Y1 - 2017

N2 - Acetyl xylan esterase (AXE) catalyzes the hydrolysis of the acetyl bonds present in plant cell wall polysaccharides. Here, we determined the crystal structure of AXE from Aspergillus luchuensis (AlAXEA), providing the three-dimensional structure of an enzyme in the Esterase_phb family. AlAXEA shares its core α/β-hydrolase fold structure with esterases in other families, but it has an extended central β-sheet at both its ends and an extra loop. Structural comparison with a ferulic acid esterase (FAE) from Aspergillus niger indicated that AlAXEA has a conserved catalytic machinery: a catalytic triad (Ser119, His259, and Asp202) and an oxyanion hole (Cys40 and Ser120). Near the catalytic triad of AlAXEA, two aromatic residues (Tyr39 and Trp160) form small pockets at both sides. Homology models of fungal FAEs in the same Esterase_phb family have wide pockets at the corresponding sites because they have residues with smaller side chains (Pro, Ser, and Gly). Mutants with sitedirected mutations at Tyr39 showed a substrate specificity similar to that of the wild-type enzyme, whereas those with mutations at Trp160 acquired an expanded substrate specificity. Interestingly, the Trp160 mutants acquired weak but significant type B-like FAE activity. Moreover, the engineered enzymes exhibited ferulic acid-releasing activity from wheat arabinoxylan.

AB - Acetyl xylan esterase (AXE) catalyzes the hydrolysis of the acetyl bonds present in plant cell wall polysaccharides. Here, we determined the crystal structure of AXE from Aspergillus luchuensis (AlAXEA), providing the three-dimensional structure of an enzyme in the Esterase_phb family. AlAXEA shares its core α/β-hydrolase fold structure with esterases in other families, but it has an extended central β-sheet at both its ends and an extra loop. Structural comparison with a ferulic acid esterase (FAE) from Aspergillus niger indicated that AlAXEA has a conserved catalytic machinery: a catalytic triad (Ser119, His259, and Asp202) and an oxyanion hole (Cys40 and Ser120). Near the catalytic triad of AlAXEA, two aromatic residues (Tyr39 and Trp160) form small pockets at both sides. Homology models of fungal FAEs in the same Esterase_phb family have wide pockets at the corresponding sites because they have residues with smaller side chains (Pro, Ser, and Gly). Mutants with sitedirected mutations at Tyr39 showed a substrate specificity similar to that of the wild-type enzyme, whereas those with mutations at Trp160 acquired an expanded substrate specificity. Interestingly, the Trp160 mutants acquired weak but significant type B-like FAE activity. Moreover, the engineered enzymes exhibited ferulic acid-releasing activity from wheat arabinoxylan.

KW - aspergillus luchuensis

KW - carboxylesterase

KW - catalytic triad

KW - enzyme structure

KW - ESTHER database

KW - X-ray crystallography

KW - a/ß-hydrolase fold

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U2 - 10.1128/AEM.01251-17

DO - 10.1128/AEM.01251-17

M3 - Article

VL - 83

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

SN - 0099-2240

IS - 20

M1 - e01251-17

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