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- Name help_outline 4-imidazolone-5-propanoate Identifier CHEBI:77893 Charge -1 Formula C6H7N2O3 InChIKeyhelp_outline MYNHYKDPSRPBNZ-UHFFFAOYSA-N SMILEShelp_outline [O-]C(=O)CC[c-]1[nH]c[nH+]c1=O 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,264 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline N-formimidoyl-L-glutamate Identifier CHEBI:58928 Charge -1 Formula C6H9N2O4 InChIKeyhelp_outline NRXIKWMTVXPVEF-BYPYZUCNSA-M SMILEShelp_outline [H]C(=[NH2+])N[C@@H](CCC([O-])=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:23660 | RHEA:23661 | RHEA:23662 | RHEA:23663 | |
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Publications
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A catalytic mechanism revealed by the crystal structures of the imidazolonepropionase from Bacillus subtilis.
Yu Y., Liang Y.-H., Brostromer E., Quan J.-M., Panjikar S., Dong Y.-H., Su X.-D.
Imidazolonepropionase (EC 3.5.2.7) catalyzes the third step in the universal histidine degradation pathway, hydrolyzing the carbon-nitrogen bonds in 4-imidazolone-5-propionic acid to yield N-formimino-l-glutamic acid. Here we report the crystal structures of the Bacillus subtilis imidazolonepropio ... >> More
Imidazolonepropionase (EC 3.5.2.7) catalyzes the third step in the universal histidine degradation pathway, hydrolyzing the carbon-nitrogen bonds in 4-imidazolone-5-propionic acid to yield N-formimino-l-glutamic acid. Here we report the crystal structures of the Bacillus subtilis imidazolonepropionase and its complex at 2.0-A resolution with substrate analog imidazole-4-acetic acid sodium (I4AA). The structure of the native enzyme contains two domains, a TIM (triose-phosphate isomerase) barrel domain with two insertions and a small beta-sandwich domain. The TIM barrel domain is quite similar to the members of the alpha/beta barrel metallo-dependent hydrolase superfamily, especially to Escherichia coli cytosine deaminase. A metal ion was found in the central cavity of the TIM barrel and was tightly coordinated to residues His-80, His-82, His-249, Asp-324, and a water molecule. X-ray fluorescence scan analysis confirmed that the bound metal ion was a zinc ion. An acetate ion, 6 A away from the zinc ion, was also found in the potential active site. In the complex structure with I4AA, a substrate analog, I4AA replaced the acetate ion and contacted with Arg-89, Try-102, Tyr-152, His-185, and Glu-252, further defining and confirming the active site. The detailed structural studies allowed us to propose a zinc-activated nucleophilic attack mechanism for the hydrolysis reaction catalyzed by the enzyme. << Less