Which base will pair up with G?
The rules of base pairing (or nucleotide pairing) are: A with T: the purine adenine (A) always pairs with the pyrimidine thymine (T) C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)
What does wobble base pairing allow?
The four main wobble base pairs are guanine-uracil (G-U), hypoxanthine-uracil (I-U), hypoxanthine-adenine (I-A), and hypoxanthine-cytosine (I-C)….tRNA base pairing schemes.
| tRNA 5′ anticodon base | mRNA 3′ codon base (Crick) | mRNA 3′ codon base (Revised) |
|---|---|---|
| G | C or U | C or U |
| U | A or G | A, G, U, or (C) |
| I | A, C, or U | A, C, or U |
What is the purpose of wobble base pairing?
Wobble base pairs play an important role in codon-anticodon interactions. Among the most frequent of wobble base pairs are G · T(U) base pairing which arises as a result of keto–enol tautomerism and A · C base pairing which is based on amino–imino tautomerism (Fig. 1.7).
Is GT A base pairing?
Purine-pyrimidine base-pairing of AT or GC or UA (in RNA) results in proper duplex structure. The only other purine-pyrimidine pairings would be AC and GT and UG (in RNA); these pairings are mismatches because the patterns of hydrogen donors and acceptors do not correspond.
Can two purine bases pair together?
Two purines and two pyrimidines together would simply take up too much space to be able to fit in the space between the two strands. The only pairs that can create hydrogen bonds in that space are adenine with thymine and cytosine with guanine. A and T form two hydrogen bonds while C and G form three.
Why are wobble base pairs less stable?
This fact implies that each tRNA anticodon must wobble with one or more nucleotides to recognize all codons in a synonymous codon family [3]. A wobble base-pair is a non-Watson-Crick base pairing between two nucleotides in RNA molecules and hence it is less stable than a Watson-Crick base pairing.
How does wobble work?
The wobble position of a codon refers to the 3rd nucleotide in a codon. This nucleotide has two major characteristics: Binding of a codon in an mRNA the cognate tRNA is much “looser” in the third position of the codon. This permits several types of non-Watson–Crick base pairing to occur at the third codon position.
Are base pairs and nucleotides the same thing?
Base pairs often are used to measure the size of an individual gene within a DNA molecule. The total number of base pairs is equal to the number of nucleotides in one of the strands (each nucleotide consists of a base pair, a deoxyribose sugar, and a phosphate group).
Which base pairing system is correct?
A DNA molecule consists of 4 base pairs. They are adenine, guanine, cytosine and thymine—adenosine pairs with thymine using two hydrogen bonds. Thus, the correct base pairing is Adenine-Thymine: option (a).
Can purines pair with purines?
Thus, purine-purine cannot pair with each other due to the unavailability of the required space to bond together in the DNA double helix.
What makes the G · you wobble base pair unique?
The G·U wobble base pair also has unique chemical, structural, dynamic and ligand-binding properties, which can only be partially mimicked by Watson–Crick base pairs or other mispairs.
How many tRNAs are required for wobble pairing?
The minimum requirement to satisfy all possible codons (61 excluding three stop codons) is 32 tRNAs. That is 31 tRNAs for the amino acids and one initiation codon. Wobble pairing rules. Watson-Crick base pairs are shown in bold. Parentheses denote bindings that work but will be favoured less.
Why are G · you wobble pairs important to RNA?
G·U wobble pairs embedded within A-form RNA helices have a distinctive structure that results from the displacement of the bases of the G·U pair relative to the bases of Watson–Crick pairs.
How are wobble base pairs related to Watson-Crick?
The thermodynamic stability of a wobble base pair is comparable to that of a Watson-Crick base pair. Wobble base pairs are fundamental in RNA secondary structure and are critical for the proper translation of the genetic code .