Pyrroline-5-carboxylate reductase

Pyrroline-5-carboxylate reductase 1 decamer, Human

Identifiers

EC no.

1.5.1.2

CAS no.

9029-17-8

Databases

IntEnz

IntEnz view

BRENDA

BRENDA entry

ExPASy

NiceZyme view

KEGG

KEGG entry

MetaCyc

metabolic pathway

PRIAM

profile

PDB structures

RCSB PDB PDBe PDBsum

Gene Ontology

AmiGO / QuickGO

Search
PMC	articles
PubMed	articles
NCBI	proteins

In enzymology, a pyrroline-5-carboxylate reductase (EC 1.5.1.2) is an enzyme that catalyzes the chemical reaction

L-proline + NAD(P)+

\rightleftharpoons

1-pyrroline-5-carboxylate + NAD(P)H + H⁺

The 3 substrates of this enzyme are L-proline, NAD⁺, and NADP⁺, whereas its 4 products are 1-pyrroline-5-carboxylate, NADH, NADPH, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-proline:NAD(P)+ 5-oxidoreductase. Other names in common use include proline oxidase, L-proline oxidase, 1-pyrroline-5-carboxylate reductase, NADPH-L-Delta1-pyrroline carboxylic acid reductase, and L-proline-NAD(P)+ 5-oxidoreductase. This enzyme participates in arginine and proline metabolism.

Structural studies

As of late 2007, 5 structures have been solved for this class of enzymes, with PDB accession codes 2AHR, 2GER, 2GR9, 2GRA, and 2IZZ.

Human genes

PYCR1, nuclear gene for mitochondrial protein
PYCR2, nuclear gene for mitochondrial protein
PYCR3 (formerly PYCRL), cytosolic protein

References

Adams E; Goldstone A (1960). "Hydroxyproline metabolism. III. Enzymatic synthesis of hydroxyproline from Delta1-pyrroline-3-hydroxy-5-carboxylate". The Journal of Biological Chemistry. 235 (12): 3499–3503. doi:10.1016/S0021-9258(18)64497-7. PMID 13681369.
Meister A, Radhakrishnan AN, Buckley SD (1957). "Enzymatic synthesis of L-pipecolic acid and L-proline". The Journal of Biological Chemistry. 229 (2): 789–800. doi:10.1016/S0021-9258(19)63684-7. PMID 13502341.
Smith ME; Greenberg DM (1956). "Characterization of an enzyme reducing pyrroline-5-carboxylate to proline". Nature. 177 (4520): 1130. Bibcode:1956Natur.177.1130S. doi:10.1038/1771130a0. PMID 13334497. S2CID 4298013.
Yura T; Vogel HJ (1959). "Pyrroline-5-carboxylate reductase of Neurospora crassa: partial purification and some properties". The Journal of Biological Chemistry. 234 (2): 335–338. doi:10.1016/S0021-9258(18)70299-8. PMID 13630905.

Metabolism: Protein metabolism, synthesis and catabolism enzymes

Essential amino acids are in Capitals

K→acetyl-CoA

LYSINE→	Saccharopine dehydrogenase Glutaryl-CoA dehydrogenase
LEUCINE→	3-Hydroxybutyryl-CoA dehydrogenase Branched-chain amino acid aminotransferase Branched-chain alpha-keto acid dehydrogenase complex Enoyl-CoA hydratase HMG-CoA lyase HMG-CoA reductase Isovaleryl coenzyme A dehydrogenase α-Ketoisocaproate dioxygenase Leucine 2,3-aminomutase Methylcrotonyl-CoA carboxylase Methylglutaconyl-CoA hydratase (See Template:Leucine metabolism in humans – this diagram does not include the pathway for β-leucine synthesis via leucine 2,3-aminomutase)
TRYPTOPHAN→	Indoleamine 2,3-dioxygenase/Tryptophan 2,3-dioxygenase Arylformamidase Kynureninase 3-hydroxyanthranilate oxidase Aminocarboxymuconate-semialdehyde decarboxylase Aminomuconate-semialdehyde dehydrogenase
PHENYLALANINE→tyrosine→	(see below)

G→pyruvate
→citrate

glycine→serine→	Serine hydroxymethyltransferase Serine dehydratase glycine→creatine: Guanidinoacetate N-methyltransferase Creatine kinase
alanine→	Alanine transaminase
cysteine→	D-cysteine desulfhydrase
threonine→	L-threonine dehydrogenase

G→glutamate→
α-ketoglutarate

HISTIDINE→	Histidine ammonia-lyase Urocanate hydratase Formiminotransferase cyclodeaminase
proline→	Proline oxidase Pyrroline-5-carboxylate reductase 1-Pyrroline-5-carboxylate dehydrogenase/ALDH4A1 PYCR1
arginine→	Ornithine aminotransferase Ornithine decarboxylase Agmatinase
→alpha-ketoglutarate→TCA	Glutamate dehydrogenase
Other	cysteine+glutamate→glutathione: Gamma-glutamylcysteine synthetase Glutathione synthetase Gamma-glutamyl transpeptidase glutamate→glutamine: Glutamine synthetase Glutaminase

G→propionyl-CoA→
succinyl-CoA

VALINE→	Branched-chain amino acid aminotransferase Branched-chain alpha-keto acid dehydrogenase complex Enoyl-CoA hydratase 3-hydroxyisobutyryl-CoA hydrolase 3-hydroxyisobutyrate dehydrogenase Methylmalonate semialdehyde dehydrogenase
ISOLEUCINE→	Branched-chain amino acid aminotransferase Branched-chain alpha-keto acid dehydrogenase complex 3-hydroxy-2-methylbutyryl-CoA dehydrogenase
METHIONINE→	generation of homocysteine: Methionine adenosyltransferase Adenosylhomocysteinase regeneration of methionine: Methionine synthase/Homocysteine methyltransferase Betaine-homocysteine methyltransferase conversion to cysteine: Cystathionine beta synthase Cystathionine gamma-lyase
THREONINE→	Threonine aldolase
→succinyl-CoA→TCA	Propionyl-CoA carboxylase Methylmalonyl CoA epimerase Methylmalonyl-CoA mutase

G→fumarate

PHENYLALANINE→tyrosine→	Phenylalanine hydroxylase Tyrosine aminotransferase 4-Hydroxyphenylpyruvate dioxygenase Homogentisate 1,2-dioxygenase Fumarylacetoacetate hydrolase tyrosine→melanin: Tyrosinase

G→oxaloacetate

asparagine→aspartate→	Asparaginase/Asparagine synthetase Aspartate transaminase

v t e Oxidoreductases: CH-NH (EC 1.5)
1.5.1: NAD or NADP acceptor	Dihydrofolate reductase Saccharopine dehydrogenase Methylenetetrahydrofolate reductase
1.5.3: oxygen acceptor	Dihydrobenzophenanthridine oxidase Sarcosine oxidase Proline oxidase
1.5.5: quinone acceptor	Electron-transferring-flavoprotein dehydrogenase
1.5.99	Sarcosine dehydrogenase Cytokinin dehydrogenase

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)