1iyn

Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights for its instability

spinqualitylabelsall models 1iyn, resolution 1.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1iyn is a 1 chain structure with sequence from Nicotiana tabacum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.6Å Ligands: HEM, NA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q8LNY5_TOBAC Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed 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. Crystal structure of chloroplastic ascorbate peroxidase from tobacco plants and structural insights into its instability.,Wada K, Tada T, Nakamura Y, Ishikawa T, Yabuta Y, Yoshimura K, Shigeoka S, Nishimura K J Biochem. 2003 Aug;134(2):239-44. PMID:12966073 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ascorbate peroxidase 3D structures

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