What is the Difference Between Watson and Crick and Hoogsteen Base Pairing?
🆚 Go to Comparative Table 🆚The difference between Watson-Crick base pairing and Hoogsteen base pairing lies in the geometric arrangement and hydrogen bonding patterns of the nucleotide bases in DNA.
In Watson-Crick base pairing, which is the most common base pairing in DNA, the hydrogen bonding occurs between the N3 position of thymine and the N1 position of adenine. Watson-Crick base pairs are formed as a result of complementary interactions, and adenine-thymine and cytosine-guanine are the most common types.
On the other hand, Hoogsteen base pairing is a variation of base pairing in nucleic acids, such as the A•T pair. In this arrangement, the hydrogen bonding occurs between the N7 position of the purine base (as a hydrogen bond acceptor) and the C6 amino group (as a donor), which bind the Watson–Crick (N3–C4) face of the pyrimidine base. Hoogsteen base pairs have shorter hydrogen bond lengths, significantly larger angles of hydrogen bonds, and larger angles between the hydrogen bonds compared to Watson-Crick base pairs.
Hoogsteen base pairing can lead to the formation of triplex DNA oligonucleotide structures, with the Hoogsteen base pairs in the major groove of the Watson-Crick duplex. This type of base pairing is observed in alternative structures, such as the four-stranded G-quadruplex.
Comparative Table: Watson vs Crick vs Hoogsteen Base Pairing
Watson and Crick base pairing is the standard method that describes the formation of base pairs between nitrogenous bases in DNA, while Hoogsteen base pairing is an alternative way of forming base pairs. Here is a comparison table highlighting the differences between Watson and Crick and Hoogsteen base pairing:
| Feature | Watson and Crick Base Pairing | Hoogsteen Base Pairing |
|---|---|---|
| Discoverers | James Watson and Francis Crick (1953) | Karst Hoogsteen (1959) |
| Purine Rotation | No rotation | 180° rotation |
| Adenine Conformation | Anti conformation | Syn conformation |
| Base Pair Stability | Stable | Less stable |
| Angle of Glycosidic Bonds | Smaller | Larger |
| DNA Structure | Double helix | Triplex (major groove) |
| Occurrence | Majority of nucleotide bases in DNA | Occurs when DNA is damaged or bound to other molecules (like drugs or proteins) |
In Watson and Crick base pairing, adenine forms hydrogen bonds with thymine, and guanine forms hydrogen bonds with cytosine. In contrast, in Hoogsteen base pairing, the adenine base rotates by 180° and forms hydrogen bonds with a base on the same strand, rather than across strands as in Watson and Crick base pairing. This rotation results in a different angle of glycosidic bonds and a changed DNA structure, leading to a triplex DNA oligonucleotide structure with Hoogsteen base pairs in the major groove of the Watson-Crick duplex.
- Nucleotide vs Base
- Base Sequence vs Amino Acid Sequence
- Base Excision Repair vs Nucleotide Excision Repair
- DNA vs RNA Nucleotide
- Cytosine vs Thymine
- Tris vs Tris Base
- DNA vs RNA
- Van der Waals vs Hydrogen Bonds
- Hydrogen Bond vs Covalent Bond
- Nucleotide vs Nucleic Acid
- Frameshift Mutation vs Base Substitution Mutation
- Cytosine vs Cysteine
- Purine vs Pyrimidine
- DNA vs RNA Structure
- Guanine vs Guanosine
- Adenine vs Guanine
- Coding vs Noncoding DNA
- Tris Base vs Tris HCl
- Thymine vs Thymidine