Tuberculinic acid

Tuberculinic acid is a noncanonical nucleic acid initially identified as the poison of Tubercle bacillus (=Mycobacterium tuberculosis), the principal causative bacterium of tuberculosis. Its discovery was one of the most important landmarks in understanding tuberculosis and in molecular biology. It is regarded as the most toxic component of the bacillus. It was from this compound that DNA methylation was discovered as it was the first molecule found to contain 5-methylcytosine. In addition it contains thymine, guanine and cytosine.