6AID

Structural insights into the unique polylactate degrading mechanism of Thermobifida alba cutinase

6AID の概要

• エントリーDOI: 10.2210/pdb6aid/pdb
• 関連するPDBエントリー: 3VIS 3WYN
• 分子名称: Esterase, CALCIUM ION, ethyl (2R)-2-oxidanylpropanoate, ... (6 entities in total)
• 機能のキーワード: hydrolase
• 由来する生物種: Thermobifida alba
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 30752.27

構造登録者

Kitadokoro, K.,Kakara, M.,Matsui, S.,Osokoshi, R.,Thumarat, U.,Kawai, F.,Kamitani, S. (登録日: 2018-08-22, 公開日: 2019-02-27, 最終更新日: 2023-11-15)

主引用文献

Kitadokoro, K.,Kakara, M.,Matsui, S.,Osokoshi, R.,Thumarat, U.,Kawai, F.,Kamitani, S.
Structural insights into the unique polylactate-degrading mechanism of Thermobifida alba cutinase.
Febs J., 286:2087-2098, 2019

PubMed Abstract: Cutinases are enzymes known to degrade polyester-type plastics. Est119, a plastic-degrading type of cutinase from Thermobifida alba AHK119 (herein called Ta_cut), shows a broad substrate specificity toward polyesters, and can degrade substrates including polylactic acid (PLA). However, the PLA-degrading mechanism of cutinases is still poorly understood. Here, we report the structure complexes of cutinase with ethyl lactate (EL), the constitutional unit. From this complex structure, the electron density maps clearly showed one lactate (LAC) and one EL occupying different positions in the active site cleft. The binding mode of EL is assumed to show a figure prior to reaction and LAC is an after-reaction product. These complex structures demonstrate the role of active site residues in the esterase reaction and substrate recognition. The complex structures were compared with other documented complex structures of cutinases and with the structure of PETase from Ideonella sakaiensis. The amino acid residues involved in substrate interaction are highly conserved among these enzymes. Thus, mapping the precise interactions in the Ta_cut and EL complex will pave the way for understanding the plastic-degrading mechanism of cutinases and suggest ways of creating more potent enzymes by structural protein engineering.

PubMed: 30761732
DOI: 10.1111/febs.14781

実験手法

X-RAY DIFFRACTION (1.3 Å)