Gene Ontology annotation through association of InterPro records with GO terms
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Gene Ontology annotation based on curation of immunofluorescence data
Automatic Gene Ontology annotation based on Rhea mapping
Electronic Gene Ontology annotations created by ARBA machine learning models
Combined Automated Annotation using Multiple IEA Methods
Architecture of the human interactome defines protein communities and disease networks.
Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.
Cloning and expression of cDNA of human delta 4-3-oxosteroid 5 beta-reductase and substrate specificity of the expressed enzyme.
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In the reported COS-cell expression assay, human AKR1D1 had high activity toward the tested bile-acid intermediates, smaller positive cortisol/testosterone activity and no observed progesterone/androstenedione activity under those conditions. Later purified-enzyme measurements establish a broader substrate range.
"Transfection of the cDNA into COS cells resulted in the expression of an active enzyme with a high activity toward the bile acid intermediates 7 alpha,12 alpha-dihydroxy-4-cholesten-3-one and 7 alpha-hydroxy-4-cholesten-3-one."
4-cholesten-7alpha-ol-3-one is reduced to 5beta-cholestan-7alpha-ol-3-one
4-cholesten-7alpha, 12alpha-diol-3-one is reduced to 5beta-cholesten-7alpha, 12alpha-diol-3-one
Synthesis of bile acids and bile salts via 7alpha-hydroxycholesterol
4-cholesten-7alpha,24(S)-diol-3-one is reduced to 5beta-cholestan-7alpha,24(S)-diol-3-one
4-cholesten-7alpha,12alpha,24(S)-triol-3-one is reduced to 5beta-cholestan-7alpha,12alpha,24(S)-triol-3-one
Synthesis of bile acids and bile salts via 24-hydroxycholesterol
Synthesis of bile acids and bile salts via 27-hydroxycholesterol
4-cholesten-7alpha,12alpha,27-triol-3-one is reduced to 5beta-cholestan-7alpha,12alpha,27-triol-3-one
4-cholesten-7alpha,27-diol-3-one is reduced to 5beta-cholestan-7alpha,27-diol-3-one
UniProtKB entry P51857 (AKR1D1, human) - curated record
Substrate specificity and inhibitor analyses of human steroid 5β-reductase (AKR1D1).
Crystal structure of human liver Delta4-3-ketosteroid 5beta-reductase (AKR1D1) and implications for substrate binding and catalysis.
Conversion of human steroid 5β-reductase (AKR1D1) into 3β-hydroxysteroid dehydrogenase by single point mutation E120H: example of perfect enzyme engineering.
Genomic organization of a human 5beta-reductase and its pseudogene and substrate selectivity of the expressed enzyme.
Aldo-keto reductases AKR1C1, AKR1C2 and AKR1C3 may enhance progesterone metabolism in ovarian endometriosis.
AKR1D1 primary-source and PAINT checks, 2026-09-20
OpenScientist focused review of AKR1D1 aldose, monooxygenase and alcohol-reduction specificity, 2026-09-21
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The report argued that AKR1D1 is specialized for 5beta reduction and that Glu120 distinguishes it from general carbonyl-reducing AKRs.
"AKR1D1 is a specialist Δ4-3-oxosteroid 5β-reductase whose defining Glu120 substitution repurposes the AKR catalytic histidine"
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The report kept the 17beta-HSD side reaction as an open full-text question.
"the 17β-HSD (RHEA) term the one that most warrants a full-text re-read before a hard call"
In-Depth Dissection of the P133R Mutation in Steroid 5β-Reductase (AKR1D1): A Molecular Basis of Bile Acid Deficiency.
Infant cholestasis patient with a novel missense mutation in the AKR1D1 gene successfully treated by early adequate supplementation with chenodeoxycholic acid: A case report and review of the literature.
AKR1D1 and CYP7B1 mutations in patients with inborn errors of bile acid metabolism: Possibly underdiagnosed diseases.
Recurrent AKR1D1 c.580-13T>A Variant: A Cause of Δ(4)-3-Oxosteroid-5β-Reductase Deficiency.
Healthy Patients With AKR1D1 Mutation Not Requiring Primary Bile Acid Therapy: A Case Series.
Variants in AKR1D1 and Infant Mortality: Should Bile Acid Screening be a Routine Part of Newborn Screening?
Characterization of disease-related 5beta-reductase (AKR1D1) mutations reveals their potential to cause bile acid deficiency.
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The 2010 preparation showed no change in P133R cofactor affinity; this finding was later superseded.
"this mutant displayed no change in cofactor affinity"
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Tested variants reduced protein expression and activity in HEK293 cells despite similar mRNA levels.
"Although these enzymes were equally expressed based on mRNA levels, protein expression and functional activity were dramatically reduced."
The enzymes, regulation, and genetics of bile acid synthesis.