scholarly journals The thiostrepton A tryptophan methyltransferase TsrM catalyses a cob(II)alamin-dependent methyl transfer reaction

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Alhosna Benjdia ◽  
Stéphane Pierre ◽  
Carmen Gherasim ◽  
Alain Guillot ◽  
Manon Carmona ◽  
...  
Keyword(s):  
Transfer Reaction ◽  
Methyl Transfer

Methyl-transfer reaction to alkylthiol catalyzed by a simple vitamin B12 model complex using zinc powder

2011 ◽  
Vol 368 (1) ◽  
pp. 194-199 ◽  
Author(s):  
Ling Pan ◽  
Keishiro Tahara ◽  
Takahiro Masuko ◽  
Yoshio Hisaeda
Keyword(s):  
Vitamin B12 ◽  
Transfer Reaction ◽  
Zinc Powder ◽  
Methyl Transfer ◽  
Model Complex

Electrochemical Methyl-transfer Reaction to Alkylthiol Catalyzed by Hydrophobic Vitamin B12

2009 ◽  
Vol 38 (1) ◽  
pp. 26-27 ◽  
Author(s):  
Ling Pan ◽  
Hisashi Shimakoshi ◽  
Yoshio Hisaeda
Keyword(s):  
Vitamin B12 ◽  
Transfer Reaction ◽  
Methyl Transfer

scholarly journals Flagellin lysine methyltransferase FliB catalyzes a [4Fe-4S] mediated methyl transfer reaction

2021 ◽  
Vol 17 (11) ◽  
pp. e1010052
Author(s):  
Chu Wang ◽  
Christian Nehls ◽  
Dirk Baabe ◽  
Olaf Burghaus ◽  
Robert Hurwitz ◽  
...  
Keyword(s):  
Transfer Reaction ◽  
Radical Mechanism ◽  
Zero Field ◽  
Paramagnetic Resonance ◽  
Methyl Transfer ◽  
Lysine Residues ◽  
Oxygen Sensitive ◽  
Flagellar Filament

The methyltransferase FliB posttranslationally modifies surface-exposed ɛ-N-lysine residues of flagellin, the protomer of the flagellar filament in Salmonella enterica (S. enterica). Flagellin methylation, reported originally in 1959, was recently shown to enhance host cell adhesion and invasion by increasing the flagellar hydrophobicity. The role of FliB in this process, however, remained enigmatic. In this study, we investigated the properties and mechanisms of FliB from S. enterica in vivo and in vitro. We show that FliB is an S-adenosylmethionine (SAM) dependent methyltransferase, forming a membrane associated oligomer that modifies flagellin in the bacterial cytosol. Using X-band electron paramagnetic resonance (EPR) spectroscopy, zero-field 57Fe Mössbauer spectroscopy, methylation assays and chromatography coupled mass spectrometry (MS) analysis, we further found that FliB contains an oxygen sensitive [4Fe-4S] cluster that is essential for the methyl transfer reaction and might mediate a radical mechanism. Our data indicate that the [4Fe-4S] cluster is coordinated by a cysteine rich motif in FliB that is highly conserved among multiple genera of the Enterobacteriaceae family.

Methyl Transfer Reaction from Monomethyltin Reagent under Palladium(0) Catalysis: A Versatile Method for Labeling with Carbon-11.

ChemInform ◽  
2006 ◽  
Vol 37 (17) ◽  
Author(s):  
Mickael Huiban ◽  
Aline Huet ◽  
Louisa Barre ◽  
Franck Sobrio ◽  
Eric Fouquet ◽  
...  
Keyword(s):  
Transfer Reaction ◽  
Methyl Transfer

scholarly journals Exploration of the Activation Mechanism of the Epigenetic Regulator MLL3: A QM/MM Study

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1051
Author(s):  
Sebastián Miranda-Rojas ◽  
Kevin Blanco-Esperguez ◽  
Iñaki Tuñón ◽  
Johannes Kästner ◽  
Fernando Mendizábal
Keyword(s):  
Transfer Reaction ◽  
Activation Mechanism ◽  
Epigenetic Mark ◽  
Regulation Mechanism ◽  
Salt Bridges ◽  
Conformational Restriction ◽  
Histone 3 ◽  
Methyl Transfer ◽  
Epigenetic Regulator

The mixed lineage leukemia 3 or MLL3 is the enzyme in charge of the writing of an epigenetic mark through the methylation of lysine 4 from the N-terminal domain of histone 3 and its deregulation has been related to several cancer lines. An interesting feature of this enzyme comes from its regulation mechanism, which involves its binding to an activating dimer before it can be catalytically functional. Once the trimer is formed, the reaction mechanism proceeds through the deprotonation of the lysine followed by the methyl-transfer reaction. Here we present a detailed exploration of the activation mechanism through a QM/MM approach focusing on both steps of the reaction, aiming to provide new insights into the deprotonation process and the role of the catalytic machinery in the methyl-transfer reaction. Our finding suggests that the source of the activation mechanism comes from conformational restriction mediated by the formation of a network of salt-bridges between MLL3 and one of the activating subunits, which restricts and stabilizes the positioning of several residues relevant for the catalysis. New insights into the deprotonation mechanism of lysine are provided, identifying a valine residue as crucial in the positioning of the water molecule in charge of the process. Finally, a tyrosine residue was found to assist the methyl transfer from SAM to the target lysine.

scholarly journals Biochemical characterization of the methylmercaptopropionate:cob(I)alamin methyltransferase fromMethanosarcina acetivorans

2019 ◽  
Author(s):  
He Fu ◽  
Michelle N. Goettge ◽  
William W. Metcalf
Keyword(s):  
Transfer Reaction ◽  
Biochemical Characterization ◽  
Detailed Knowledge ◽  
Methanosarcina Acetivorans ◽  
Coenzyme M ◽  
Metabolic Intermediate ◽  
High Substrate ◽  
Methyl Transfer ◽  
Substrate Concentrations

ABSTRACTMethanogenesis from methylated substrates is initiated by substrate specific methyltransferases that generate the central metabolic intermediate methyl-coenzyme M. This reaction involves a methyl-corrinoid protein intermediate and one or two cognate methyltransferases. Based on genetic data, theMethanosarcina acetivoransMtpC (corrinoid protein) and MtpA (methyltransferase) proteins were suggested to catalyze the methylmercaptopropionate(MMPA):Coenzyme M (CoM) methyl transfer reaction without a second methyltransferase. To test this, MtpA was purified after overexpression in its native host and characterized biochemically. MtpA catalyzes a robust methyl transfer reaction using free methylcob(III)alamin as the donor and mercaptopropionate (MPA) as the acceptor, withkcatof 0.315 s-1and apparentKmfor MPA of 12 μM. CoM did not serve as a methyl acceptor, thus a second, unidentified methyltransferase is required to catalyze the full MMPA:CoM methyl transfer reaction. The physiologically relevant methylation of cob(I)alamin with MMPA, which is thermodynamically unfavorable, could also be demonstrated, but only at high substrate concentrations. Methylation of cob(I)alamin with methanol, dimethylsulfide, dimethylamine and methyl-CoM was not observed, even at high substrate concentrations. Although the corrinoid protein MtpC was poorly expressed alone, a stable MtpA/MtpC complex was obtained when both proteins were co-expressed. Biochemical characterization of this complex was not feasible because the corrinoid cofactor of this complex was in the inactive Co(II) state and could not be reactivated by incubation with strong reductants. The MtsF protein, comprised of both corrinoid and methyltransferase domains, co-purifies with the MtpA/MtpC, suggesting that it may be involved in MMPA metabolism.IMPORTANCEMMPA is an environmentally significant molecule produced by degradation of the abundant marine metabolite dimethylsulfoniopropionate, which plays a significant role in the biogeochemical cycles of both carbon and sulfur, with ramifications for ecosystem productivity and climate homeostasis. Detailed knowledge of the mechanisms for MMPA production and consumption is key to understanding steady state levels of this compound in the biosphere. Unfortunately, the biochemistry required for MMPA catabolism under anoxic conditions is poorly characterized. The data reported here validate the suggestion that the MtpA protein catalyzes the first step in methanogenic catabolism of MMPA. However, the enzyme does not catalyze a proposed second step required to produce the key intermediate methyl-CoM. Therefore, additional enzymes required for methanogenic MMPA catabolism await discovery.

On the Methyl-Transfer Reaction in Crystalline Methyl 2-(Methylthio)benzenesulfonate: a Thermally Induced Non-Topochemical Solid-State Reaction

1991 ◽  
Vol 74 (3) ◽  
pp. 662-669 ◽  
Author(s):  
P. Venugopalan ◽  
K. Venkatesan ◽  
J�rg Klausen ◽  
Elisabeth Novotny-Bregger ◽  
Christian Leumann ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Transfer Reaction ◽  
Thermally Induced ◽  
Methyl Transfer
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