Three-dimensional structure of the catalytic core of acetylxylan esterase from Trichoderma reesei: Insights into the deacetylation mechanism

Nina Hakulinen (Corresponding Author), Maija Tenkanen, Juha Rouvinen

Research output: Contribution to journalArticleScientificpeer-review

52 Citations (Scopus)

Abstract

Acetylxylan esterase from Trichoderma reesei removes acetyl side groups from xylan. The crystal structure of the catalytic core of the enzyme was solved at 1.9 Å resolution. The core has an α/β/α sandwich fold, similar to that of homologous acetylxylan esterase from Penicillium purpurogenum and cutinase from Fusarium solani. All three enzymes belong to family 5 of the carbohydrate esterases and the superfamily of the α/β hydrolase fold. Evidently, the enzymes have diverged from a common ancestor and they share the same catalytic mechanism. The catalytic machinery of acetylxylan esterase from T. reesei was studied by comparison with cutinase, the catalytic site of which is well known. Acetylxylan esterase is a pure serine esterase having a catalytic triad (Ser90, His187, and Asp175) and an oxyanion hole (Thr13 N, and Thr13 Oγ). Although the catalytic triad of acetylxylan esterase has been reported previously, there has been no mention of the oxyanion hole. A model for the binding of substrates is presented on the basis of the docking of xylose. Acetylxylan esterase from T. reesei is able to deacetylate both mono- and double-acetylated residues, but it is not able to remove acetyl groups located close to large side groups such as 4-O-methylglucuronic acid. If the xylopyranoside residue is double-acetylated, both acetyl groups are removed by the catalytic triad: first one acetyl group is removed and then the residue is reorientated so that the nucleophilic oxygen of serine can attack the second acetyl group.

Original languageEnglish
Pages (from-to)180 - 190
Number of pages11
JournalJournal of Structural Biology
Volume132
Issue number3
DOIs
Publication statusPublished - 2000
MoE publication typeA1 Journal article-refereed

Fingerprint

acetylxylan esterase
Trichoderma
Catalytic Domain
Enzymes
Xylans
Penicillium
Xylose
Fusarium
Hydrolases
Esterases
Serine
Carbohydrates
Oxygen

Cite this

@article{51ecc8a755ee483bbacde36896afe5cc,
title = "Three-dimensional structure of the catalytic core of acetylxylan esterase from Trichoderma reesei: Insights into the deacetylation mechanism",
abstract = "Acetylxylan esterase from Trichoderma reesei removes acetyl side groups from xylan. The crystal structure of the catalytic core of the enzyme was solved at 1.9 {\AA} resolution. The core has an α/β/α sandwich fold, similar to that of homologous acetylxylan esterase from Penicillium purpurogenum and cutinase from Fusarium solani. All three enzymes belong to family 5 of the carbohydrate esterases and the superfamily of the α/β hydrolase fold. Evidently, the enzymes have diverged from a common ancestor and they share the same catalytic mechanism. The catalytic machinery of acetylxylan esterase from T. reesei was studied by comparison with cutinase, the catalytic site of which is well known. Acetylxylan esterase is a pure serine esterase having a catalytic triad (Ser90, His187, and Asp175) and an oxyanion hole (Thr13 N, and Thr13 Oγ). Although the catalytic triad of acetylxylan esterase has been reported previously, there has been no mention of the oxyanion hole. A model for the binding of substrates is presented on the basis of the docking of xylose. Acetylxylan esterase from T. reesei is able to deacetylate both mono- and double-acetylated residues, but it is not able to remove acetyl groups located close to large side groups such as 4-O-methylglucuronic acid. If the xylopyranoside residue is double-acetylated, both acetyl groups are removed by the catalytic triad: first one acetyl group is removed and then the residue is reorientated so that the nucleophilic oxygen of serine can attack the second acetyl group.",
author = "Nina Hakulinen and Maija Tenkanen and Juha Rouvinen",
year = "2000",
doi = "10.1006/jsbi.2000.4318",
language = "English",
volume = "132",
pages = "180 -- 190",
journal = "Journal of Structural Biology",
issn = "1047-8477",
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Three-dimensional structure of the catalytic core of acetylxylan esterase from Trichoderma reesei : Insights into the deacetylation mechanism. / Hakulinen, Nina (Corresponding Author); Tenkanen, Maija; Rouvinen, Juha.

In: Journal of Structural Biology, Vol. 132, No. 3, 2000, p. 180 - 190.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Three-dimensional structure of the catalytic core of acetylxylan esterase from Trichoderma reesei

T2 - Insights into the deacetylation mechanism

AU - Hakulinen, Nina

AU - Tenkanen, Maija

AU - Rouvinen, Juha

PY - 2000

Y1 - 2000

N2 - Acetylxylan esterase from Trichoderma reesei removes acetyl side groups from xylan. The crystal structure of the catalytic core of the enzyme was solved at 1.9 Å resolution. The core has an α/β/α sandwich fold, similar to that of homologous acetylxylan esterase from Penicillium purpurogenum and cutinase from Fusarium solani. All three enzymes belong to family 5 of the carbohydrate esterases and the superfamily of the α/β hydrolase fold. Evidently, the enzymes have diverged from a common ancestor and they share the same catalytic mechanism. The catalytic machinery of acetylxylan esterase from T. reesei was studied by comparison with cutinase, the catalytic site of which is well known. Acetylxylan esterase is a pure serine esterase having a catalytic triad (Ser90, His187, and Asp175) and an oxyanion hole (Thr13 N, and Thr13 Oγ). Although the catalytic triad of acetylxylan esterase has been reported previously, there has been no mention of the oxyanion hole. A model for the binding of substrates is presented on the basis of the docking of xylose. Acetylxylan esterase from T. reesei is able to deacetylate both mono- and double-acetylated residues, but it is not able to remove acetyl groups located close to large side groups such as 4-O-methylglucuronic acid. If the xylopyranoside residue is double-acetylated, both acetyl groups are removed by the catalytic triad: first one acetyl group is removed and then the residue is reorientated so that the nucleophilic oxygen of serine can attack the second acetyl group.

AB - Acetylxylan esterase from Trichoderma reesei removes acetyl side groups from xylan. The crystal structure of the catalytic core of the enzyme was solved at 1.9 Å resolution. The core has an α/β/α sandwich fold, similar to that of homologous acetylxylan esterase from Penicillium purpurogenum and cutinase from Fusarium solani. All three enzymes belong to family 5 of the carbohydrate esterases and the superfamily of the α/β hydrolase fold. Evidently, the enzymes have diverged from a common ancestor and they share the same catalytic mechanism. The catalytic machinery of acetylxylan esterase from T. reesei was studied by comparison with cutinase, the catalytic site of which is well known. Acetylxylan esterase is a pure serine esterase having a catalytic triad (Ser90, His187, and Asp175) and an oxyanion hole (Thr13 N, and Thr13 Oγ). Although the catalytic triad of acetylxylan esterase has been reported previously, there has been no mention of the oxyanion hole. A model for the binding of substrates is presented on the basis of the docking of xylose. Acetylxylan esterase from T. reesei is able to deacetylate both mono- and double-acetylated residues, but it is not able to remove acetyl groups located close to large side groups such as 4-O-methylglucuronic acid. If the xylopyranoside residue is double-acetylated, both acetyl groups are removed by the catalytic triad: first one acetyl group is removed and then the residue is reorientated so that the nucleophilic oxygen of serine can attack the second acetyl group.

U2 - 10.1006/jsbi.2000.4318

DO - 10.1006/jsbi.2000.4318

M3 - Article

VL - 132

SP - 180

EP - 190

JO - Journal of Structural Biology

JF - Journal of Structural Biology

SN - 1047-8477

IS - 3

ER -