6J42

Crystal Structure of Wild Type KatB, a manganese catalase from Anabaena

6J42 の概要

• エントリーDOI: 10.2210/pdb6j42/pdb
• 分子名称: Alr3090 protein, MANGANESE (II) ION, CALCIUM ION, ... (5 entities in total)
• 機能のキーワード: enzyme, catalase, manganese catalase, oxidoreductase
• 由来する生物種: Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576)
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 80292.09

構造登録者

Bihani, S.C.,Chakravarty, D.,Ballal, A. (登録日: 2019-01-07, 公開日: 2020-01-15, 最終更新日: 2023-11-22)

主引用文献

Chakravarty, D.,Bihani, S.C.,Banerjee, M.,Ballal, A.
Novel molecular insights into the anti-oxidative stress response and structure-function of a salt-inducible cyanobacterial Mn-catalase.
Plant Cell Environ, 42:2508-2521, 2019

PubMed Abstract: KatB, a salt-inducible Mn-catalase, protects the cyanobacterium Anabaena from salinity/oxidative stress. In this report, we provide distinctive insights into the biological-biochemical function of KatB at the molecular level. Anabaena overexpressing the wild-type KatB protein (KatBWT) detoxified H O efficiently, showing reduced burden of reactive oxygen species compared with the strain overproducing KatBF2V (wherein F-2 is replaced by V). Correspondingly, the KatBWT protein also displayed several folds more activity than KatBF2V. Interestingly, the KatB variants with large hydrophobic amino acids (F/W/Y) were more compact, showed enhanced activity, and were resistant to thermal/chemical denaturation than variants with smaller residues (G/A/V) at the second position. X-ray crystallography-based analysis showed that F-2 was required for appropriate interactions between two subunits. These contacts provided stability to the hexamer, making it more compact. F-2, through its interaction with F-66 and W-43, formed the proper hydrophobic pocket that held the active site together. Consequently, only residues that supported activity (i.e., F/Y/W) were selected at the second position in Mn-catalases during evolution. This study (a) demonstrates that modification of nonactive site residues can alter the response of catalases to environmental stress and (b) has expanded the scope of amino acids that can be targeted for rational protein engineering in plants.

PubMed: 30993731
DOI: 10.1111/pce.13563

実験手法

X-RAY DIFFRACTION (2.492 Å)