1IYN
Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights for its instability
Summary for 1IYN
| Entry DOI | 10.2210/pdb1iyn/pdb |
| Descriptor | Chloroplastic ascorbate peroxidase, SODIUM ION, PROTOPORPHYRIN IX CONTAINING FE, ... (4 entities in total) |
| Functional Keywords | ascorbate, peroxidase, hydrogen peroxide, tobacco plant, stromal ascorbate peroxidase, oxidoreductase |
| Biological source | Nicotiana tabacum (common tobacco) |
| Total number of polymer chains | 1 |
| Total formula weight | 32944.63 |
| Authors | Wada, K.,Tada, T.,Nakamura, Y. (deposition date: 2002-09-03, release date: 2003-09-03, Last modification date: 2023-10-25) |
| Primary citation | Wada, K.,Tada, T.,Nakamura, Y.,Ishikawa, T.,Yabuta, Y.,Yoshimura, K.,Shigeoka, S.,Nishimura, K. Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights into its instability J.BIOCHEM.(TOKYO), 134:239-244, 2003 Cited by PubMed Abstract: Ascorbate peroxidase (APX) is a heme-containing protein that plays a central role in scavenging H(2)O(2) in higher plants. The structure of stromal APX (sAPX) was determined at 1.6 A to an R-factor of 19.1% and an R-free-factor of 22.3%. The electrostatic potential of the gamma-channel that connects the molecular surface of sAPX to the gamma-edge of heme was more positive than that of cytosolic APX (cAPX) from pea, so sAPX might bind more easily with ascorbate than cAPX. The overall structure of sAPX was similar to those of cAPX from pea and cytochrome c peroxidase (CCP) from yeast, with a substantial difference in a loop structure located in the vicinity of the heme. The side chain of Arg169 in sAPX corresponding to His169 in cAPX and His181 in CCP extended in the opposite direction from the heme, forming two hydrogen bonds with carbonyl groups in the loop structure. The rapid inactivation of sAPX might be due to the characteristic conformation of Arg169 owing to the loop structure of sAPX. PubMed: 12966073DOI: 10.1093/jb/mvg136 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.6 Å) |
Structure validation
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