3A15

Crystal Structure of Substrate-Free Form of Aldoxime Dehydratase (OxdRE)

Summary for 3A15

• Entry DOI: 10.2210/pdb3a15/pdb
• Related: 3A16 3A17 3A18
• Descriptor: Aldoxime dehydratase, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• Functional Keywords: beta barrel, heme protein, lyase
• Biological source: Rhodococcus erythropolis
• Total number of polymer chains: 4
• Total formula weight: 170796.45

Authors

Sawai, H.,Sugimoto, H.,Kato, Y.,Asano, Y.,Shiro, Y.,Aono, S. (deposition date: 2009-03-26, release date: 2009-09-08, Last modification date: 2024-03-13)

Primary citation

Sawai, H.,Sugimoto, H.,Kato, Y.,Asano, Y.,Shiro, Y.,Aono, S.
X-ray crystal structure of michaelis complex of aldoxime dehydratase
J.Biol.Chem., 284:32089-32096, 2009

PubMed Abstract: Aldoxime dehydratase (Oxd) catalyzes the dehydration of aldoximes (R-CH=N-OH) to their corresponding nitrile (R-C triple bond N). Oxd is a heme-containing enzyme that catalyzes the dehydration reaction as its physiological function. We have determined the first two structures of Oxd: the substrate-free OxdRE at 1.8 A resolution and the n-butyraldoxime- and propionaldoxime-bound OxdREs at 1.8 and 1.6 A resolutions, respectively. Unlike other heme enzymes, the organic substrate is directly bound to the heme iron in OxdRE. We determined the structure of the Michaelis complex of OxdRE by using the unique substrate binding and activity regulation properties of Oxd. The Michaelis complex was prepared by x-ray cryoradiolytic reduction of the ferric dead-end complex in which Oxd contains a Fe(3+) heme form. The crystal structures reveal the mechanism of substrate recognition and the catalysis of OxdRE.

PubMed: 19740758
DOI: 10.1074/jbc.M109.018762

Experimental method

X-RAY DIFFRACTION (1.79 Å)