Literature summary for 5.4.99.18 extracted from

Hoskins, A.A.; Morar, M.; Kappock, T.J.; Mathews, I.I.; Zaugg, J.B.; Barder, T.E.; Peng, P.; Okamoto, A.; Ealick, S.E.; Stubbe, J.
N5-CAIR mutase: role of a CO2 binding site and substrate movement in catalysis (2007), Biochemistry, 46, 2842-2855.

Search for more literature for 5.4.99.18

Cloned(Commentary)

Cloned (Comment)	Organism
expression in Escherichia coli	Escherichia coli

Crystallization (Commentary)

Crystallization (Comment)	Organism
wild-type cocrystallized with 4-nitroaminoimidazole ribonucleotide and mutants H45N and H45Q soaked with 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	Escherichia coli

Protein Variants

Protein Variants	Comment	Organism
H45N	very low catalytic activity	Escherichia coli
H45Q	very low catalytic activity	Escherichia coli
H45W	very low catalytic activity	Escherichia coli

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.0226	-	5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	wild-type, pH 7.5, 23°C	Escherichia coli

Organism

Organism	UniProt	Comment	Textmining
Escherichia coli	P0AG18	-	-

Reaction

Reaction	Comment	Organism	Reaction ID
5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole = 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	common, buried carboxylate or CO2 binding site for substrate and product in a hydrophobic pocket, in which the carboxylate or CO2 interacts with backbone amides. The carboxylate orients the substrate for proton transfer from His45 to 5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole to form an enzyme-bound aminoimidazole ribonucleotide and CO2 intermediate. subsequent movement of the aminoimidazole moiety reorients it for addition of CO2 at C4 to generate iso-5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate. H5 is now in a position to remove a C4 proton to produce 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	Escherichia coli	a

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	-	Escherichia coli	5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole	-	r
5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole	-	Escherichia coli	5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	-	r

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism	Structure
0.0004	-	5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	mutant H45W, pH 7.5, 23°C	Escherichia coli
0.0012	-	5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	mutant H45Q, pH 7.5, 23°C	Escherichia coli
0.0021	-	5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole	mutant H45Q, pH 7.5, 23°C	Escherichia coli
15.5	-	5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole	wild-type, pH 7.5, 23°C	Escherichia coli
15.6	-	5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate	wild-type, pH 7.5, 23°C	Escherichia coli

Use of this online version of BRENDA is free under the CC BY 4.0 license. See terms of use for full details.

Release 2023.1 (January 2023)