1m7s
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Crystal Structure Analysis of Catalase CatF of Pseudomonas syringae
OverviewOverview
Catalase CatF of Pseudomonas syringae has been identified phylogenetically, as a clade 1 catalase, closely related to plant catalases, a group from, which no structure has been determined. The structure of CatF has been, refined at 1.8 A resolution by using X-ray synchrotron data collected from, a crystal flash-cooled with liquid nitrogen. The crystallographic, agreement factors R and R(free) are, respectively, 18.3% and 24.0%. The, asymmetric unit of the crystal contains a whole molecule that shows, accurate 222-point group symmetry. The crystallized enzyme is a, homotetramer of subunits with 484 residues, some 26 residues shorter than, predicted from the DNA sequence. Mass spectrometry analysis confirmed the, absence of 26 N-terminal residues, possibly removed by a periplasmic, transport system. The core structure of the CatF subunit was closely, related to seven other catalases with root-mean-square deviations (RMSDs), of 368 core Calpha atoms of 0.99-1.30 A. The heme component of CatF is, heme b in the same orientation that is found in Escherichia coli, hydroperoxidase II, an orientation that is flipped 180 degrees with, respect the orientation of the heme in bovine liver catalase. NADPH is not, found in the structure of CatF because key residues required for, nucleotide binding are missing; 2129 water molecules were refined into the, model. Water occupancy in the main or perpendicular channel of CatF varied, among the four subunits from two to five in the region between the heme, and the conserved Asp150. A comparison of the water occupancy in this, region with the same region in other catalases reveals significant, differences among the catalases.
About this StructureAbout this Structure
1M7S is a Single protein structure of sequence from Pseudomonas syringae with HEM as ligand. Active as Catalase, with EC number 1.11.1.6 Full crystallographic information is available from OCA.
ReferenceReference
Structure of the Clade 1 catalase, CatF of Pseudomonas syringae, at 1.8 A resolution., Carpena X, Soriano M, Klotz MG, Duckworth HW, Donald LJ, Melik-Adamyan W, Fita I, Loewen PC, Proteins. 2003 Feb 15;50(3):423-36. PMID:12557185
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