Key Bases and Base Pairs in Bioinformatics
Definition
The following five bases are referred to as the Canonical Bases:
- Purine bases: Adenine , Guanine
- Pyrimidine bases: Cytosine , Thymine , Uracil
Description
Thymine is only used in DNA, while Uracil is used in RNA. Therefore, by checking whether or is used in the data, one can tell whether it is a DNA or RNA base sequence.
A Base Pair is formed by two bases capable of hydrogen bonding, with one selected from each of the purine and pyrimidine bases. Among them, there are possible cases.
and are connected by 2 hydrogen bonds, and by 3 hydrogen bonds. DNA has a double helical structure due to base pairing. Therefore, if is on one strand, must be on the opposite strand. For example, with a DNA sample like the one above, knowing one strand is enough. Thus, when acquiring data, one can simply read the left side and record it like this: ACCGTTAC. The significance of the double helical structure is essentially a ‘backup’. Indeed, RNA, which is made of a single strand and has an unstable structure, often causes problems. However, DNA can stably pass on genetic information to future generations as the opposite strand can serve as a reference when problems arise on one strand.