Video Experimental Relacionado

Updated: May 3, 2026

Profiling of Methyltransferases and Other S-adenosyl-L-homocysteine-binding Proteins by Capture Compound Mass Spectrometry CCMS

Profiling of Methyltransferases and Other S-adenosyl-L-homocysteine-binding Proteins by Capture Compound Mass Spectrometry CCMS

Published on: December 21, 2010

Elucidación de la estereospecificidad de las C-metiltransferasas a partir de las trans-AT Polyketide Synthases

Xinqiang Xie¹, Chaitan Khosla², David E Cane¹

¹Department of Chemistry, Brown University , Box H, Providence, Rhode Island 02912-9108, United States.

Journal of the American Chemical Society

|April 22, 2017

Resumen

Las C-metiltransferasas dependientes de S-Adenosil metionina (SAM) catalizan la metilación crucial de C2 en la síntesis de policetida bacteriana. Este estudio revela que estas enzimas producen exclusivamente el estereoisómero (2R) de los intermediarios 2-metil-3-cetoacil-ACP.

Área de la Ciencia:

La bioquímica
Biología molecular
Química orgánica

Sus antecedentes:

Las C-metiltransferasas dependientes de la S-adenosil metionina (SAM) son enzimas clave en la biosíntesis de los policetidos bacterianos.
Estas enzimas realizan la metilación C2 de los intermediarios de la proteína portadora 3-cetoacil-acil (ACP), en particular en las trans-aciltransferasas (AT) poliquetidas.
Comprender el resultado estereoquímico de estas reacciones de metilación es crítico para elucidar las vías de ensamblaje de policetidos.

Objetivo del estudio:

Para determinar la estereoquímica de la reacción de C-metilación catalizada por las C-metiltransferasas bacterianas.
Para investigar la preferencia estereocímica de BonMT2, una C-metiltransferasa de la poliquetida de ácido bongrekico.
Confirmar el resultado estereoquímico con otras C-metiltransferasas implicadas en la biosíntesis del bacileno, la difficidina y la mupirocina.

Principales métodos:

Síntesis quimioenzimática del 3-ketopentanoil-ACP.
Incubación de 3-ketopentanoyl-ACP con S-Adenosyl methionine (SAM) y C-metiltransferasas (BonMT2, BaeMT9, DifMT1, MupMT1).
El ensayo de la cetorreductaza acoplada (KR) y el análisis de espectrometría de masas por cromatografía quiral de gases (GC-MS) de los ésteres metílicos derivados.

Principales resultados:

BonMT2 generado exclusivamente con (2R) 2-metil-3-cetopentanilo-ACP a partir de 3-cetopentanilo-ACP y SAM.
Se confirmó que el resultado estereoquímico era exclusivamente (2R) para tres C-metiltransferasas adicionales: BaeMT9, DifMT1 y MupMT1.
El análisis quiral GC-MS de ésteres metílicos confirmó la formación exclusiva del estereoisómero (2R).

Conclusiones:

Las C-metiltransferasas bacterianas involucradas en las trans-AT poliquetidas exhiben un estricto control estereoquímico, produciendo exclusivamente el producto (2R) -2-metil-3-cetoacil-ACP.
Esta estereospecificidad se conserva a través de múltiples C-metiltransferasas de diferentes vías poliquetídicas.
Los hallazgos proporcionan información crucial sobre los mecanismos estereoquímicos que rigen la biosíntesis de los policetidos bacterianos.

Más Videos Relacionados

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

Published on: November 22, 2014

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

From a Natural Product to Its Biosynthetic Gene Cluster: A Demonstration Using Polyketomycin from Streptomyces diastatochromogenes Tü6028

Published on: January 13, 2017

Videos de Conceptos Relacionados

tRNA Activation

tRNA Activation

Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...

Allosteric Proteins-ATCase

Allosteric Proteins-ATCase

Binding sites linkages can regulate a protein's function. For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...

Peptidoglycan Synthesis

Peptidoglycan Synthesis

Structure of PeptidoglycanPeptidoglycan is a vital structural component of the bacterial cell wall, providing mechanical strength and shape to the cell. It consists of repeating units of two sugars—N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)—linked by β-1,4 glycosidic bonds. These sugar chains are cross-linked by short peptide chains, forming a mesh-like polymer that surrounds the bacterial plasma membrane.Cytoplasmic Phase – Precursor SynthesisPeptidoglycan...

Coordination of Gene Expression Processes in Bacteria

Coordination of Gene Expression Processes in Bacteria

The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...