4 research outputs found
A Spirobicyclo[3.1.0]Terpene from the Investigation of Sesquiterpene Synthases from <i>Lactarius deliciosus</i>
Milk
cap mushrooms in the genus Lactarius are
known to produce a wide variety of terpene natural products. However,
their repertoire of terpene biosynthetic enzymes has not been fully
explored. In this study, several candidate sesquiterpene synthases
were identified from the genome of the saffron milk cap mushroom L. deliciosus and expressed in a sesquiterpene-overproducing Escherichia coli strain. In addition to enzymes that produce
several known terpenes, we identified an enzyme belonging to a previously
unknown clade of sesquiterpene synthases that produces a terpene with
a unique spiro-tricyclic scaffold. These findings add to the rich
diversity of terpene scaffolds and mushroom terpene synthases and
are valuable for biotechnological applications in producing these
terpenoids
Glycyl Radical Enzymes Catalyzing the Dehydration of Two Isomers of <i>N</i>‑Methyl-4-hydroxyproline
The
various isomers of hydroxyproline (HP) are widely
distributed
in nature, serving as key components of structural proteins, while
their quaternized betaine derivatives function as osmoprotectants
in many organisms. Aerobic bacteria degrade HPs through a variety
of well-studied mechanisms. Recent studies show that certain anaerobic
bacteria degrade HPs through distinct mechanisms, involving the O2-sensitive glycyl radical enzymes (GREs) t4L-HP dehydratase
(HypD) and t4D-HP C–N lyase (HplG). Here, we report the discovery
of two more GREs, N-methyl c4L-HP dehydratase (HpyG)
and N-methyl c4D-HP dehydratase (HpzG), which catalyze
radical-mediated dehydration of the two N-methyl-c4HP
enantiomers, while also displaying significant activities toward their
unmethylated substrates. Both GREs are associated with homologues
of pyrroline-5-carboxylate reductase, which catalyze reduction of
their products N-methyl-pyrroline-5-carboxylate to
form N-methyl-proline. Crystal structures of HpyG
and HpzG in complex with their substrates revealed active site architectures
distinct from that of HypD and provided insights into the mechanism
of enantioselective radical-mediated dehydration. Our research further
expands the repertoire of diverse chemical mechanisms involved in
the bacterial metabolism of highly prevalent HP isomers and derivatives
in the anaerobic biosphere
Glycyl Radical Enzymes Catalyzing the Dehydration of Two Isomers of <i>N</i>‑Methyl-4-hydroxyproline
The
various isomers of hydroxyproline (HP) are widely
distributed
in nature, serving as key components of structural proteins, while
their quaternized betaine derivatives function as osmoprotectants
in many organisms. Aerobic bacteria degrade HPs through a variety
of well-studied mechanisms. Recent studies show that certain anaerobic
bacteria degrade HPs through distinct mechanisms, involving the O2-sensitive glycyl radical enzymes (GREs) t4L-HP dehydratase
(HypD) and t4D-HP C–N lyase (HplG). Here, we report the discovery
of two more GREs, N-methyl c4L-HP dehydratase (HpyG)
and N-methyl c4D-HP dehydratase (HpzG), which catalyze
radical-mediated dehydration of the two N-methyl-c4HP
enantiomers, while also displaying significant activities toward their
unmethylated substrates. Both GREs are associated with homologues
of pyrroline-5-carboxylate reductase, which catalyze reduction of
their products N-methyl-pyrroline-5-carboxylate to
form N-methyl-proline. Crystal structures of HpyG
and HpzG in complex with their substrates revealed active site architectures
distinct from that of HypD and provided insights into the mechanism
of enantioselective radical-mediated dehydration. Our research further
expands the repertoire of diverse chemical mechanisms involved in
the bacterial metabolism of highly prevalent HP isomers and derivatives
in the anaerobic biosphere
Glycyl Radical Enzymes Catalyzing the Dehydration of Two Isomers of <i>N</i>‑Methyl-4-hydroxyproline
The
various isomers of hydroxyproline (HP) are widely
distributed
in nature, serving as key components of structural proteins, while
their quaternized betaine derivatives function as osmoprotectants
in many organisms. Aerobic bacteria degrade HPs through a variety
of well-studied mechanisms. Recent studies show that certain anaerobic
bacteria degrade HPs through distinct mechanisms, involving the O2-sensitive glycyl radical enzymes (GREs) t4L-HP dehydratase
(HypD) and t4D-HP C–N lyase (HplG). Here, we report the discovery
of two more GREs, N-methyl c4L-HP dehydratase (HpyG)
and N-methyl c4D-HP dehydratase (HpzG), which catalyze
radical-mediated dehydration of the two N-methyl-c4HP
enantiomers, while also displaying significant activities toward their
unmethylated substrates. Both GREs are associated with homologues
of pyrroline-5-carboxylate reductase, which catalyze reduction of
their products N-methyl-pyrroline-5-carboxylate to
form N-methyl-proline. Crystal structures of HpyG
and HpzG in complex with their substrates revealed active site architectures
distinct from that of HypD and provided insights into the mechanism
of enantioselective radical-mediated dehydration. Our research further
expands the repertoire of diverse chemical mechanisms involved in
the bacterial metabolism of highly prevalent HP isomers and derivatives
in the anaerobic biosphere