6J42
Crystal Structure of Wild Type KatB, a manganese catalase from Anabaena
Summary for 6J42
| Entry DOI | 10.2210/pdb6j42/pdb |
| Descriptor | Alr3090 protein, MANGANESE (II) ION, CALCIUM ION, ... (5 entities in total) |
| Functional Keywords | enzyme, catalase, manganese catalase, oxidoreductase |
| Biological source | Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576) |
| Total number of polymer chains | 3 |
| Total formula weight | 80292.09 |
| Authors | Bihani, S.C.,Chakravarty, D.,Ballal, A. (deposition date: 2019-01-07, release date: 2020-01-15, Last modification date: 2023-11-22) |
| Primary citation | 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 Cited by 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: 30993731DOI: 10.1111/pce.13563 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.492 Å) |
Structure validation
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