1J0B

Crystal Structure Analysis of the ACC deaminase homologue complexed with inhibitor

Summary for 1J0B

• Entry DOI: 10.2210/pdb1j0b/pdb
• Related: 1F2D 1J0A 1J0C 1J0D 1J0E
• Descriptor: 1-aminocyclopropane-1-carboxylate deaminase, N-[3-HYDROXY-2-METHYL-5-PHOSPHONOOXYMETHYL-PYRIDIN-4-Y-LMETHYL]-1-AMINO-CYCLOPROPANECARBOXYLIC ACID (3 entities in total)
• Functional Keywords: plp dependent, lyase
• Biological source: Pyrococcus horikoshii
• Total number of polymer chains: 24
• Total formula weight: 853561.68

Authors

Fujino, A.,Ose, T.,Honma, M.,Yao, M.,Tanaka, I. (deposition date: 2002-11-12, release date: 2003-05-12, Last modification date: 2024-12-25)

Primary citation

Fujino, A.,Ose, T.,Yao, M.,Tokiwano, T.,Honma, M.,Watanabe, N.,Tanaka, I.
Structural and enzymatic properties of 1-aminocyclopropane-1-carboxylate deaminase homologue from Pyrococcus horikoshii
J.Mol.Biol., 341:999-1013, 2004

PubMed Abstract: 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.

PubMed: 15328614
DOI: 10.1016/j.jmb.2004.06.062

Experimental method

X-RAY DIFFRACTION (2.7 Å)