7ZOS
Class 1 Phytoglobin from Sugar beet (BvPgb1.2)
Summary for 7ZOS
| Entry DOI | 10.2210/pdb7zos/pdb |
| Descriptor | Non-symbiotic hemoglobin class 1, PROTOPORPHYRIN IX CONTAINING FE, CYANIDE ION, ... (5 entities in total) |
| Functional Keywords | plant hemoglobin, phytoglobin, nitrogen metabolism, redox balance, oxygen binding |
| Biological source | Beta vulgaris |
| Total number of polymer chains | 1 |
| Total formula weight | 20107.76 |
| Authors | Nyblom, M.,Christensen, S.,Eriksson, N.,Bulow, L. (deposition date: 2022-04-26, release date: 2022-09-07, Last modification date: 2024-02-07) |
| Primary citation | Christensen, S.,Groth, L.,Leiva-Eriksson, N.,Nyblom, M.,Bulow, L. Oxidative Implications of Substituting a Conserved Cysteine Residue in Sugar Beet Phytoglobin BvPgb 1.2. Antioxidants, 11:-, 2022 Cited by PubMed Abstract: Phytoglobins (Pgbs) are plant-originating heme proteins of the globin superfamily with varying degrees of hexacoordination. Pgbs have a conserved cysteine residue, the role of which is poorly understood. In this paper, we investigated the functional and structural role of cysteine in BvPgb1.2, a Class 1 Pgb from sugar beet (), by constructing an alanine-substituted mutant (Cys86Ala). The substitution had little impact on structure, dimerization, and heme loss as determined by X-ray crystallography, size-exclusion chromatography, and an apomyoglobin-based heme-loss assay, respectively. The substitution significantly affected other important biochemical properties. The autoxidation rate increased 16.7- and 14.4-fold for the mutant versus the native protein at 25 °C and 37 °C, respectively. Thermal stability similarly increased for the mutant by ~2.5 °C as measured by nano-differential scanning fluorimetry. Monitoring peroxidase activity over 7 days showed a 60% activity decrease in the native protein, from 33.7 to 20.2 U/mg protein. When comparing the two proteins, the mutant displayed a remarkable enzymatic stability as activity remained relatively constant throughout, albeit at a lower level, ~12 U/mg protein. This suggests that cysteine plays an important role in BvPgb1.2 function and stability, despite having seemingly little effect on its tertiary and quaternary structure. PubMed: 36009334DOI: 10.3390/antiox11081615 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.9 Å) |
Structure validation
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