Base pair

In molecular biology, two nucleotides on opposite complementary DNA or RNA strands that are connected by hydrogen bonds are called a base pair (often abbreviated bp).

In the Watson-Crick base pairing, adenine (A) forms a base pair with thymine (T), and guanine (G) with cytosine (C) in DNA. In RNA, thymine is replaced by uracil (U). But there is also non-Watson-Crick base pairing with other hydrogen bonding patterns, especially in RNA.

Other pages

• DNA
• Nucleobase

Other websites

• DAN - webserver version of the EMBOSS tool for calculating melting temperatures

General references

• Watson JD, Baker TA, Bell SP, Gann A, Levine M, Losick R. (2004). Molecular Biology of the Gene. 5th ed. Pearson Benjamin Cummings: CSHL Press. See esp. ch. 6 and 9.