Literature summary for 4.1.1.23 extracted from

Paojinda, P.; Imprasittichai, W.; Krungkrai, S.R.; Palacpac, N.M.Q.; Horii, T.; Krungkrai, J.
Bifunctional activity of fused Plasmodium falciparum orotate phosphoribosyltransferase and orotidine 5'-monophosphate decarboxylase (2018), Parasitol. Int., 67, 79-84 .

Cloned(Commentary)

Cloned (Comment)	Organism
functional recombinant expression of the His-tagged chimeric fusion enzyme in Escherichia coli	Plasmodium falciparum

Protein Variants

Protein Variants	Comment	Organism
additional information	construction of a chimeric fusion enzyme from the last two enzymes in the pyrimidine biosynthetic pathway in the inversed order by having a C-terminal orotate phosphoribosyltransferase (OPRT) and an N-terminal orotidine 5'-monophosphate decarboxylase (OMPDC) as OMPDC-OPRT in Plasmodium falciparum, the chimeric mutant acts as a bifunctional enzyme. The activitiy, although unstable, is stabilized by the substrate and product during purification and long-term storage. The kcat is selectively enhanced up to three orders of magnitude, while the Km is not much affected and remains at low micromolar levels when compared to the monofunctional enzymes. The fusion of the two enzymes creates a super-enzyme with perfect catalytic power and more flexibility	Plasmodium falciparum

Inhibitors

Inhibitors	Comment	Organism	Structure
6-aza-UMP	competitive inhibition	Plasmodium falciparum
UMP	competitive inhibition	Plasmodium falciparum

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism
additional information	-	additional information	Michaelis-Menten kinetics	Plasmodium falciparum
0.002	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant bifunctional enzyme, OMPDC activity	Plasmodium falciparum
0.0105	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant multienzyme complex, OMPDC activity	Plasmodium falciparum
0.0134	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant monofunctional enzyme, OMPDC activity	Plasmodium falciparum

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
158000	-	recombinant bifunctional OMPDC-OPRT enzyme, gel filtration	Plasmodium falciparum

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
Orotidine 5'-phosphate	Plasmodium falciparum	-	UMP + CO2	-	?

Organism

Organism	UniProt	Comment	Textmining
Plasmodium falciparum	Q8T6J6	-	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant His-tagged chimeric fusion enzyme from Escherichia coli by nickel affinity and anion exchange chromatography to near homogeneity	Plasmodium falciparum

Storage Stability

Storage Stability	Organism
4°C, purified recombinant bifunctional enzyme, stability property of both domains in the bifunctional enzyme in the absence or presence of 0.5 mM PRPP and 0.5 mM UMP: half-life of the OPRT activity is about 3-4 days and 3 weeks, respectively. The OMPDC activity is much more stable with half-life of about 3-4 weeks. 90% of the bifunctional protein, stored for 4 weeks, remains as a bifunctional protein band in SDS-PAGE and image analyses	Plasmodium falciparum

Organism

4°C, purified recombinant bifunctional enzyme, stability property of both domains in the bifunctional enzyme in the absence or presence of 0.5 mM PRPP and 0.5 mM UMP: half-life of the OPRT activity is about 3-4 days and 3 weeks, respectively. The OMPDC activity is much more stable with half-life of about 3-4 weeks. 90% of the bifunctional protein, stored for 4 weeks, remains as a bifunctional protein band in SDS-PAGE and image analyses

Plasmodium falciparum

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
Orotidine 5'-phosphate	-	Plasmodium falciparum	UMP + CO2	-	?

Subunits

Subunits	Comment	Organism
dimer	2 * 33000, OPRT subunits, + 2 * 38000, OMPDC subunits, SDS-PAGE	Plasmodium falciparum
More	three-dimensional structure of the bifunctional OMPDC-OPRT (residues 1-323 and 324-604, respectively) is predicted using the crystal structure of Leishmania donovani UMPS (PDB ID 3QW4) as template with OMPDC (residues 1-323) and OPRT (residues 387-604) in which residues 324-386 are not present in the homology model	Plasmodium falciparum

Synonyms

Synonyms	Comment	Organism
More	cf. EC 2.4.2.10	Plasmodium falciparum
OMPDC	-	Plasmodium falciparum
Orotidine 5'-monophosphate decarboxylase	-	Plasmodium falciparum

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism
7.5	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant monofunctional enzyme, OMPDC activity	Plasmodium falciparum
30.7	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant multienzyme complex, OMPDC activity	Plasmodium falciparum
985.8	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant bifunctional enzyme, OMPDC activity	Plasmodium falciparum

Ki Value [mM]

Ki Value [mM]	Ki Value maximum [mM]	Inhibitor	Comment	Organism
0.0001	-	6-aza-UMP	pH and temperature not specified in the publication, recombinant multienzyme complex, versus OMPDC activity	Plasmodium falciparum
0.001	-	6-aza-UMP	pH and temperature not specified in the publication, recombinant monofunctional enzyme, versus OMPDC activity	Plasmodium falciparum
0.0195	-	6-aza-UMP	pH and temperature not specified in the publication, recombinant bifunctional enzyme, versus OMPDC activity	Plasmodium falciparum
0.078	-	UMP	pH and temperature not specified in the publication, recombinant bifunctional enzyme, versus OMPDC activity	Plasmodium falciparum
0.12	-	UMP	pH and temperature not specified in the publication, recombinant multienzyme complex, versus OMPDC activity	Plasmodium falciparum
0.25	-	UMP	pH and temperature not specified in the publication, recombinant monofunctional enzyme, versus OMPDC activity	Plasmodium falciparum

General Information

General Information	Comment	Organism
evolution	fusion of the last two enzymes in the pyrimidine biosynthetic pathway in the inversed order by having a C-terminal orotate phosphoribosyltransferase (OPRT) and an N-terminal orotidine 5'-monophosphate decarboxylase (OMPDC), as OMPDC-OPRT, are described in many organisms. During evolution a gene fusion (i.e., the new gene coding for hybrid protein) is the immediate form between a stand-alone gene of a monofunctional enzyme and a gene fission of multienzyme complex (i.e., single gene from multiple smaller coding segments) responsible for protein-protein interaction, in response to different allosteric controls	Plasmodium falciparum

kcat/KM [mM/s]

kcat/KM Value [1/mMs^-1]	kcat/KM Value Maximum [1/mMs^-1]	Substrate	Comment	Organism
559.7	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant monofunctional enzyme, OMPDC activity	Plasmodium falciparum
2923.8	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant multienzyme complex, OMPDC activity	Plasmodium falciparum
492900	-	orotidine 5'-phosphate	pH and temperature not specified in the publication, recombinant bifunctional enzyme, OMPDC activity	Plasmodium falciparum