Question

In many organisms, DNA is modified by methylation. Draw the structure of 5-methylcytosine, a base that occurs with high frequency in inactive DNA.

Short answer

The structure of 5-methylcytosine is:

Step-by-step solution

Introduction

A DNA molecule is made up of helical strands comprising of nucleotide base pairs that carry genetic instructions for the growth, development, function, and reproduction all living species.

The addition of methyl groups to nucleotides in a DNA molecule changes the structure of the DNA molecule. The nucleotide sequences of DNA do not change after methylation, however the expression of methylated genes may alter.

5-Methylcytosine

When the methyl group is added to the 5^th carbon atom of cytosine without changing its base-pairing characteristics, 5-methylcytosine is generated.5-Methylcytosine has a role in gene transcription control.

Pictorial representation of methylation of cytosine