Steroid Chemistry and Biochemistry

Complete genome sequence of Comamonas testosteroni TA441 and comparative analysis of steroid degradation gene clusters across Proteobacteria and Actinomycetota

The Urinary Tract Commensal Peptoniphilus spp. Encodes a Novel 17β-Hydroxysteroid Dehydrogenase

This study identifies novel 17β-hydroxysteroid dehydrogenases in Peptoniphilus and Anaerococcus that convert androstenedione to testosterone, expanding understanding of microbial androgen metabolism in the genitourinary tract.

A sterol reductase responsible for the unusual 8(14)-unsaturation in bacterial sterol production and degradation

This paper identifies a bacterial 8,14-sterol reductase responsible for generating the 8(14)-unsaturation in sterols produced by aerobic methanotrophs and related organisms.

Degradation of biopesticidal triterpenoid saponins by the soil bacterium Arthrobacter sp. α-11c

This study isolates Arthrobacter sp. 11c, which fully degrades hederagenin-based saponins within six hours, revealing unique glycosidase gene clusters involved in saponin metabolism.

Identification of the C9-Hydrogenase for 9,17-Dioxo-1,2,3,4,10,19-Hexanorandrostan-5-oic Acid (9,17-DOHNA) and the 7α-Dehydratase Essential for Initiating β-Oxidation of the B-, C-, and D-Rings in Steroid Degradation by Comamonas testosteroni TA441

This paper identifies the C9-hydrogenase and 7α-dehydratase genes essential for β-oxidation of steroid rings in Comamonas testosteroni TA441 and characterizes their structural features.

Multigram-scale stereoselective synthesis of neurosteroid isomers by gut microbial isolates using plant biomass-derived medium

This paper identifies gut bacteria that stereoselectively synthesize neurosteroid isomers using a plant-based medium, achieving high conversion and purity without chiral purification.

Biochemical characterization of bacterial methyltransferases reveals necessary residues for sterol side-chain propylation

The paper identifies key residues in bacterial SMTs necessary for sterol side-chain propylation and shows their conservation across methylating, ethylating, and propylating SMTs.

The urinary pathobiont Actinobaculum massiliense generates androgens via the dirAB pathway

The study identifies Actinobaculum massiliense as a urinary pathobiont capable of generating androgens via the dirAB pathway, using a novel HSDH assay.

Characterization of an NADPH-dependent 17α-hydroxysteroid dehydrogenase encoded by the desF gene from the gut bacterium Clostridium scindens VPI 12708

This study quantitatively characterizes the kinetic parameters and substrate specificity of the NADPH-dependent 17α-hydroxysteroid dehydrogenase encoded by the desF gene in Clostridium scindens VPI 12708, revealing its role in epitestosterone formation.

Gut Bacteria Encode Reductases that Biotransform Steroid Hormones

Gut bacteria encode 5β-reductase, fused 3β-HSDH/Δ5-4 isomerase and Δ6-3-ketosteroid reductase enzymes acting on steroid hormones; two of these genes are enriched in female gut metagenomes.

Discovery and mechanistic characterization of a probiotic-origin 3β-OH-Δ5-6-cholesterol-5β-reductase directly converting cholesterol to coprostanol

This paper identifies a probiotic enzyme that converts cholesterol to coprostanol and links its abundance to diabetes.

7β-hydroxysteroid dehydratase Hsh3 eliminates the 7-hydroxy group of the bile salt ursodeoxycholate during degradation by Sphingobium sp. strain Chol11 and other Sphingomonadaceae

This paper identifies Hsh3, an enzyme in Sphingobium sp. strain Chol11 that degrades ursodeoxycholate by removing its 7β-hydroxy group, and shows its role in bile salt degradation and potential biotechnological applications.

Before the Black Box

The paper investigates evolutionary changes in three enzymes involved in ecdysteroid synthesis across arthropods and correlates these changes with dietary factors.

A geranylgeranyl reductase homolog required for cholesterol production in Myxococcota

This paper identifies two myxobacteria capable of cholesterol biosynthesis, reveals a distinct pathway and reductase enzyme, and provides phylogenomic evidence for complex evolutionary history of sterol biosynthesis in Myxococcota.

Aromatase-independent estrogenesis: Wood-Ljungdahl pathway likely contributed to the emergence of estrogens in the biosphere

This paper discovers aromatase-independent estrogenesis in an anaerobic bacterium, suggesting the Wood-Ljungdahl pathway may have contributed to the emergence of estrogens in the biosphere.

Identification of Dehydrogenase, Hydratase, and Aldolase Required for C17 Propionyl Residue Removal in Steroid Degradation by Comamonas testosteroni TA441: Structural and Functional Insights into the (ChsE1-ChsE2)2 and (ChsH1-ChsH2MaoC)2-(Ltp2-ChsH2DUF35)2 Complexes

This study identifies enzymes involved in C17 propionyl residue removal during steroid degradation in Comamonas testosteroni TA441 and shows structural and functional similarities to Mycobacterium tuberculosis enzymes.

Differential activity and expression of human 5β-reductase (AKR1D1) splice variants

This study examines the differential expression and activity of three AKR1D1 splice variants in human tissues and cells, showing that AKR1D1-002 is the main functional variant involved in steroid hormone metabolism.

Mammalian Cells Engineered to Produce Novel Steroids

The paper demonstrates that mammalian cells can produce novel steroids using steroid-modifying enzymes, identifying new hydroxylation sites and potential applications for drug candidate testing.