5-Methyluridine

A nucleoside derived from uridine

5-Methyluridine, also known as ribothymidine, is a nucleoside that is derived from uridine by the methylation of the 5th carbon of the uracil base. It is a component of transfer RNA (tRNA) and plays a role in the stability and function of tRNA molecules.

Structure

5-Methyluridine consists of a ribose sugar attached to a thymine base. The ribose is a five-carbon sugar that is part of the RNA backbone, and the thymine is a pyrimidine base that is methylated at the 5th carbon position. This methylation distinguishes it from uridine, which has a uracil base.

Function

In tRNA, 5-methyluridine is often found in the T_C loop, a region important for the proper folding and function of tRNA molecules. The presence of the methyl group in 5-methyluridine contributes to the hydrophobic interactions and stacking interactions that stabilize the tRNA structure.

Biosynthesis

5-Methyluridine is synthesized in cells by the methylation of uridine residues in tRNA. This process is catalyzed by specific methyltransferase enzymes that transfer a methyl group from S-adenosylmethionine to the uracil base of uridine.

Role in RNA

In addition to its role in tRNA, 5-methyluridine can also be found in other types of RNA, where it may influence the secondary structure and function of the RNA molecule. Its presence can affect the thermal stability and base pairing properties of RNA.

Related pages

• Uridine
• Thymine
• Ribose
• Transfer RNA
• Methylation

Gallery

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  3D space-filling model of ribothymidine