An Fe²⁺‐ and α‐Ketoglutarate‐Dependent Halogenase Acts on Nucleotide Substrates

Abstract

While halogenated nucleosides are used as common anticancer and antiviral drugs, naturally occurring halogenated nucleosides are rare. Adechlorin (ade) is a 2′‐chloro nucleoside natural product first identified from Actinomadura sp. ATCC 39365. However, the installation of chlorine in the ade biosynthetic pathway remains elusive. Reported herein is a Fe2+‐α‐ketoglutarate halogenase AdeV that can install a chlorine atom at the C2′ position of 2′‐deoxyadenosine monophosphate to afford 2′‐chloro‐2′‐deoxyadenosine monophosphate. Furthermore, 2′,3′‐dideoxyadenosine‐5′‐monophosphate and 2′‐deoxyinosine‐5′‐monophosphate can also be converted, albeit 20‐fold and 2‐fold, respectively, less efficiently relative to the conversion of 2′‐deoxyadenosine monophosphate. AdeV represents the first example of a Fe2+‐α‐ketoglutarate‐dependent halogenase that converts nucleotides into chlorinated analogues.

Properties of the Reactants and Their Interactions within and with the Enzyme Binding Cavity Determine Reaction Selectivities. The Case of Fe(II)/2‐Oxoglutarate Dependent Enzymes

“… Variety of ODD‐catalysed reactions. Clockwise: hydroxylations (at times leading to N/O‐demethylations or further oxidations), epoxidations (frequently preceded by hydroxylation or double bond formation in a one‐pot fashion), desaturations, (oxa)cyclisations, epimerisations and halogenations (catalysed by carrier‐dependent halogenases: SyrB2, CytC3 or ones acting on free‐standing molecules: WelO5, [70,71] WelO5*, [72] Wi‐WelO15, [73] AmbO5, [74] AdeV, [75] or DAH) [76] …”

“…carrier dependent: CytC3, [167] SyrB2, [134,135] HctB [144,145] carrier independent: WelO5, [70,71] WelO5*, [72] Wi‐WelO15, [73] AmbO5, [74] AdeV, [75] DAH [76] …”

“…Chemistry-A European Journal (frequently preceded by hydroxylation or double bond formation in a one-pot fashion), desaturations, (oxa)cyclisations, epimerisations and halogenations (catalysed by carrier-dependent halogenases: SyrB2, CytC3 or ones acting on free-standing molecules: WelO5, [70,71] WelO5*, [72] Wi-WelO15, [73] AmbO5, [74] AdeV, [75] or DAH). [76] regioselectivity than during desaturation -at a position more distant from the radical C atom.…”

Chemistry, Biosynthesis, and Biological Activity of Halogenated Compounds Produced by Marine Microorganisms

“…reactions and are the second class of halogenases. [ 169 ] These halogenases are mainly involved in the halogenation of non‐activated carbon centers on aliphatic moieties such as terminal methyl groups. The reaction is α ‐ketoglutarate dependent, tacking molecular oxygen, and can interact with inactivating carbon atoms.…”

The chloroalkaloid (−)-acutumine is biosynthesized via a Fe(II)- and 2-oxoglutarate-dependent halogenase in Menispermaceae plants

“…Here, we report the discovery of dechloroacutumine halogenase (DAH) from Menispermaceae plants, an Fe(II)-dependent and 2-oxoglutarate-dependent halogenase (2ODH) that catalyzes the terminal chlorination reaction in (−)-acutumine biosynthesis. Phylogenetic analyses suggest that DAH evolved independently from those 2ODHs previously identified from bacteria [18][19][20][21][22][23] . We show that DAH can also catalyze regioselective C-H azidation at the presence of azide anion, illustrating the promising broader utilities of 2ODH enzymes for versatile natural product derivatization.…”