1j0a

Crystal Structure Analysis of the ACC deaminase homologue

spinqualitylabelsall models 1j0a, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1j0a is a 3 chain structure with sequence from Pyrho. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: IPA, PLP, SO4 Related: 1f2d, 1j0b, 1j0c, 1j0d, 1j0e Activity: 1-aminocyclopropane-1-carboxylate deaminase, with EC number 3.5.99.7 Resources: FirstGlance, OCA, RCSB, PDBsum 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 1-Aminocyclopropane-l-carboxylate deaminase (ACCD) is a pyridoxal 5/-phosphate dependent enzyme that shows deaminase activity toward ACC, a precursor of plant hormone ethylene. ACCD from some soil bacteria has been reported to be able to break the cyclopropane ring of ACC to yield a-ketobutyrate and ammonia. We reported the crystal structure of ACCD from the yeast Hansenula saturnus in the absence/presence of substrate ACC, and proposed its ingenious reaction mechanisms. In order to study the enzyme further, we overexpressed the ACCD homologue protein (phAHP) from the fully decoded hyperthermophilic archearon, Pyrococcus horikoshii OT3. However, phAHP does not show ACCD activity at high temperature as well as at room temperature, though it has significant sequence similarity. Instead of ACCD activity, the GC-MS analysis and enzymatic method show that phAHP has deaminase activity toward L and D-serine. Here, we present the crystal structures of the native and ACC-complexed phAHP. The overall topology of the phAHP structure is very similar to that of ACCD; however, critical differences were observed around the active site. Here, the differences of enzymatic activity between phAHP and ACCD are discussed based on the structural differences of these two proteins. We suggest that the catalytic disagreement between these two enzymes comes from the difference of the residues near the pyridine ring of pyridoxal 5'-phosphate (PLP), not the difference of the catalytic residues themselves. We also propose a condition necessary in the primary sequence to have ACCD activity. Structural and enzymatic properties of 1-aminocyclopropane-1-carboxylate deaminase homologue from Pyrococcus horikoshii.,Fujino A, Ose T, Yao M, Tokiwano T, Honma M, Watanabe N, Tanaka I J Mol Biol. 2004 Aug 20;341(4):999-1013. PMID:15328614 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Deaminase

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