4754-39-6

Usage

Uses

Used in Mass Spectrometry:
5'-Deoxyadenosine is utilized as a standard in mass spectroscopy, a technique used to identify and quantify compounds based on their mass-to-charge ratio. It helps in providing accurate measurements and comparisons for various samples.
Used in Enzyme Activity Screening:
5'-Deoxyadenosine is employed as an inhibitor for screening thymidine phosphorylase activity. Thymidine phosphorylase is an enzyme involved in the salvage pathway of pyrimidine synthesis, and its activity can be crucial in certain biological processes and disease states.
Used in Enzyme Assays:
5'-Deoxyadenosine is used as a substrate in the 5'-Deoxyadenosine deaminase (DadD) assay. DadD is an enzyme that catalyzes the deamination of 5'-deoxyadenosine to inosine, which is an essential step in the regulation of nucleotide metabolism. The assay helps in studying the enzyme's function and its role in various biological processes.

Biochem/physiol Actions

5′-Deoxyadenosine is a substrate for the enzyme methylthioadenosine/S-adenosylhomocysteine (MTA/SAH) nucleosidase in microbes. 5′-Deoxyadenosine is a byproduct of cleavage of S-adenosylmethionine (SAM). High levels of 5′-Deoxyadenosine inhibits SAM dependent enzymes. It also inhibits biotin synthase (BioB) and lipoyl synthase (LipA) enzymes.

InChI:InChI=1/C10H13N5O3/c1-4-6(16)7(17)10(18-4)15-3-14-5-8(11)12-2-13-9(5)15/h2-4,6-7,10,16-17H,1H3,(H2,11,12,13)/t4-,6-,7-,10-/m1/s1

Upstream product

• 2457-80-9 5'-Deoxy-5'-methylthioadenosine 
• 5135-30-8 5'-tosyladenosine 
• 4546-55-8 N-benzoyladenosine 
• 59862-05-4 cytosylglucuronic acid 
• 1167430-57-0 1-(3-deoxy-3-fluoro-β-D-glucopyranosyl)cytosine 
• 924279-85-6 1-(2,4,6-tri-O-acetyl-3-deoxy-3-fluoro-β-D-glucopyranosyl)-N⁴-benzoyl cytosine 
• 7226-43-9 [(2R,3R,4S,5S)-3,5,6-triacetoxy-4-fluoro-tetrahydropyran-2-yl]methyl acetate 
• 14031-35-7 S-Adenosyl-L-methionine 
• 53199-56-7 S-adenosyl-L-homocysteine sulfone 
• 21127-35-5 S-adenosylselenohomocysteine selenoxide 
• 485-80-3 S-adenosyl-L-methionine 
• 785816-21-9 C₈H₁₃⁽²⁾HN₃O₇P 
• 25635-88-5 5-amino-1-(β-D-ribofuranosyl)imidazole 5'-phosphate 

Downstream Products

• 66224-66-6 adenine 
• 1237496-74-0 1-(3-methyl-2-butenylamino)-9-(5'-deoxy-β-D-ribofuranosyl)purine hydrobromide 
• 13039-75-3 5′-deoxyribose 
• 63734-70-3 8-bromo-5'-deoxy-adenosine 
• 1000003-70-2 C₃₈H₂₉N₅O₇ 
• 4680-63-1 2-amino-9-(5-deoxy-β-D-ribofuranosyl)-9H-6-thiopurine 

Relevant academic research and scientific papers

Structural Insights into the Mechanism of the Radical SAM Carbide Synthase NifB, a Key Nitrogenase Cofactor Maturating Enzyme

Nitrogenase is a key player in the global nitrogen cycle, as it catalyzes the reduction of dinitrogen into ammonia. The active site of the nitrogenase MoFe protein corresponds to a [MoFe7S9C-(R)-homocitrate] species designated FeMo-cofactor, whose biosynthesis and insertion requires the action of over a dozen maturation proteins provided by the NIF (for NItrogen Fixation) assembly machinery. Among them, the radical SAM protein NifB plays an essential role, concomitantly inserting a carbide ion and coupling two [Fe4S4] clusters to form a [Fe8S9C] precursor called NifB-co. Here we report on the X-ray structure of NifB from Methanotrix thermoacetophila at 1.95 ? resolution in a state pending the binding of one [Fe4S4] cluster substrate. The overall NifB architecture indicates that this enzyme has a single SAM binding site, which at this stage is occupied by cysteine residue 62. The structure reveals a unique ligand binding mode for the K1-cluster involving cysteine residues 29 and 128 in addition to histidine 42 and glutamate 65. The latter, together with cysteine 62, belongs to a loop inserted in the active site, likely protecting the already present [Fe4S4] clusters. These two residues regulate the sequence of events, controlling SAM dual reactivity and preventing unwanted radical-based chemistry before the K2 [Fe4S4] cluster substrate is loaded into the protein. The location of the K1-cluster, too far away from the SAM binding site, supports a mechanism in which the K2-cluster is the site of methylation.

Identification and characterization of functional homologs of nitrogenase cofactor biosynthesis protein NifB from methanogens

Nitrogenase biosynthesis protein NifB catalyzes the radical S-adenosyl-L-methionine (SAM)-dependent insertion of carbide into the M cluster, the cofactor of the molybdenum nitrogenase from Azotobacter vinelandii. Here, we report the identification and characterization of two naturally €truncated€ homologs of NifB from Methanosarcina acetivorans (NifBMa) and Methanobacterium thermoautotrophicum (NifBMt), which contain a SAM-binding domain at the N terminus but lack a domain toward the C terminus that shares homology with NifX, an accessory protein in M cluster biosynthesis. NifBMa and NifBMt are monomeric proteins containing a SAM-binding [Fe4S4] cluster (designated the SAM cluster) and a [Fe4S4]-like cluster pair (designated the K cluster) that can be processed into an [Fe8S9] precursor to the M cluster (designated the L cluster). Further, the K clusters in NifBMa and NifBMt can be converted to L clusters upon addition of SAM, which corresponds to their ability to heterologously donate L clusters to the biosynthetic machinery of A. vinelandii for further maturation into the M clusters. Perhaps even more excitingly, NifBMa and NifBMt can catalyze the removal of methyl group from SAM and the abstraction of hydrogen from this methyl group by 5€-deoxyadenosyl radical that initiates the radical-based incorporation of methyl-derived carbide into the M cluster. The successful identification of NifBMa and NifBMt as functional homologs of NifB not only enabled classification of a new subset of radical SAM methyltransferases that specialize in complex metallocluster assembly, but also provided a new tool for further characterization of the distinctive, NifB-catalyzed methyl transfer and conversion to an iron-bound carbide.

Catalysis of a new ribose carbon-insertion reaction by the molybdenum cofactor biosynthetic enzyme MoaA

MoaA, a radical S-adenosylmethionine enzyme, catalyzes the first step in molybdopterin biosynthesis. This reaction involves a complex rearrangement in which C8 of guanosine triphosphate is inserted between C2′ and C3′ of the ribose. This study identifies the site of initial hydrogen atom abstraction by the adenosyl radical and advances a mechanistic proposal for this unprecedented reaction.

Radical S-Adenosyl Methionine Enzyme BlsE Catalyzes a Radical-Mediated 1,2-Diol Dehydration during the Biosynthesis of Blasticidin S

The biosynthesis of blasticidin S has drawn attention due to the participation of the radical S-adenosyl methionine (SAM) enzyme BlsE. The original assignment of BlsE as a radical-mediated, redox-neutral decarboxylase is unusual because this reaction appears to serve no biosynthetic purpose and would need to be reversed by a subsequent carboxylation step. Furthermore, with the exception of BlsE, all other radical SAM decarboxylases reported to date are oxidative in nature. Careful analysis of the BlsE reaction, however, demonstrates that BlsE is not a decarboxylase but instead a lyase that catalyzes the dehydration of cytosylglucuronic acid (CGA) to form cytosyl-4′-keto-3′-deoxy-d-glucuronic acid, which can rapidly decarboxylate nonenzymatically in vitro. Analysis of substrate isotopologs, fluorinated analogues, as well as computational models based on X-ray crystal structures of the BlsE·SAM (2.09 ?) and BlsE·SAM·CGA (2.62 ?) complexes suggests that BlsE catalysis likely proceeds via direct elimination of water from the CGA C4′ α-hydroxyalkyl radical as opposed to 1,2-migration of the C3′-hydroxyl prior to dehydration. Biosynthetic and mechanistic implications of the revised assignment of BlsE are discussed.

The B12-independent glycerol dehydratase activating enzyme from Clostridium butyricum cleaves SAM to produce 5′-deoxyadenosine and not 5′-deoxy-5′-(methylthio)adenosine

Glycerol dehydratase activating enzyme (GD-AE) is a radical S-adenosyl-L-methionine (SAM) enzyme that installs a catalytically essential amino acid backbone radical onto glycerol dehydratase in bacteria under anaerobic conditions. Although GD-AE is closely homologous to other radical SAM activases that have been shown to cleave the S-C(5′) bond of SAM to produce 5′-deoxyadenosine (5’-dAdoH) and methionine, GD-AE from Clostridium butyricum has been reported to instead cleave the S-C(γ) bond of SAM to yield 5′-deoxy-5′-(methylthio)adenosine (MTA). Here we re-investigate the SAM cleavage reaction catalyzed by GD-AE and show that it produces the widely observed 5’-dAdoH, and not the less conventional product MTA.

HygY Is a Twitch Radical SAM Epimerase with Latent Dehydrogenase Activity Revealed upon Mutation of a Single Cysteine Residue

HygY is a SPASM/twitch radical SAM enzyme hypothesized to catalyze the C2′-epimerization of galacamine during the biosynthesis of hygromycin B. This activity is confirmed via biochemical and structural analysis of the derivatized reaction products using chemically synthesized deuterated substrate, high-resolution mass spectrometry and1H NMR. Electron paramagnetic resonance spectroscopy of the reduced enzyme is consistent with ligation of two [Fe4S4] clusters characteristic of the twitch radical SAM subgroup. HygY catalyzed epimerization proceeds with incorporation of a single solvent Hydron into the talamine product facilitated by the catalytic cysteine-183 residue. Mutation of this cysteine to alanine converts HygY from a C2′-epimerase to an C2′-dehydrogenase with comparable activity. The SPASM/twitch radical SAM enzymes often serve as anaerobic oxidases making the redox-neutral epimerases in this class rather interesting. The discovery of latent dehydrogenase activity in a twitch epimerase may therefore offer new insights into the mechanistic features that distinguish oxidative versus redox-neutral SPASM/twitch enzymes and lead to the evolution of new enzyme activities.

Reductive Cleavage of Sulfoxide and Sulfone by Two Radical S-Adenosyl- l -methionine Enzymes

Sulfoxides and sulfones are commonly found in nature as a result of thioether oxidation, whereas only a very few enzymes have been found to metabolize these compounds. Utilizing the strong reduction potential of the [4Fe-4S] cluster of radical S-adenosyl-l-methionine (SAM) enzymes, we herein report the first enzyme-catalyzed reductive cleavage of sulfoxide and sulfone. We show two radical SAM enzymes, tryptophan lyase NosL and the class C radical SAM methyltransferase NosN, are able to act on a sulfoxide SAHO and a sulfone SAHO2, both of which are structurally similar to SAM. NosL cleaves all of the three bonds (i.e., S-C(5′), S-C(γ), and S-O) connecting the sulfur center of SAHO, with a preference for S-C(5′) bond cleavage. Similar S-C cleavage activity was also found for SHAO2, but no S-O cleavage was observed. In contrast to NosL, NosN almost exclusively cleaves the S-C(5′) bonds of SAHO and SAHO2 with much higher efficiencies. Our study provides valuable insights into the [4Fe-4S] cluster-mediated reduction reactions and highlights the remarkable catalytic promiscuity of radical SAM enzymes.

Mechanistic Investigations of PoyD, a Radical S-Adenosyl- l -methionine Enzyme Catalyzing Iterative and Directional Epimerizations in Polytheonamide A Biosynthesis

Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a growing family of bioactive peptides. Among RiPPs, the bacterial toxin polytheonamide A is characterized by a unique set of post-translational modifications catalyzed by novel radical S-adenosyl-l-methionine (SAM) enzymes. Here we show that the radical SAM enzyme PoyD catalyzes in vitro polytheonamide epimerization in a C-to-N directional manner. By combining mutagenesis experiments with labeling studies and investigating the enzyme substrate promiscuity, we deciphered in detail the mechanism of PoyD. We notably identified a critical cysteine residue as a likely key H atom donor and demonstrated that PoyD belongs to a distinct family of radical SAM peptidyl epimerases. In addition, our study shows that the core peptide directly influences the epimerization pattern allowing for production of peptides with unnatural epimerization patterns.

Mechanism of a Class C Radical S-Adenosyl- l -methionine Thiazole Methyl Transferase

The past decade has seen the discovery of four different classes of radical S-adenosylmethionine (rSAM) methyltransferases that methylate unactivated carbon centers. Whereas the mechanism of class A is well understood, the molecular details of methylation by classes B-D are not. In this study, we present detailed mechanistic investigations of the class C rSAM methyltransferase TbtI involved in the biosynthesis of the potent thiopeptide antibiotic thiomuracin. TbtI C-methylates a Cys-derived thiazole during posttranslational maturation. Product analysis demonstrates that two SAM molecules are required for methylation and that one SAM (SAM1) is converted to 5′-deoxyadenosine and the second SAM (SAM2) is converted to S-adenosyl-l-homocysteine (SAH). Isotope labeling studies show that a hydrogen is transferred from the methyl group of SAM2 to the 5′-deoxyadenosine of SAM1 and the other two hydrogens of the methyl group of SAM2 appear in the methylated product. In addition, a hydrogen appears to be transferred from the β-position of the thiazole to the methyl group in the product. We also show that the methyl protons in the product can exchange with solvent. A mechanism consistent with these observations is presented that differs from other characterized radical SAM methyltransferases.

Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme

Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na+ as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M+ ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[13C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li+ to Cs+, PFL-AE activity sharply maximizes at K+, with NH4+ closely matching the efficacy of K+. PFL-AE is thus a type I M+-activated enzyme whose M+ controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.