INITIATION CODON Meaning and
Definition
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An initiation codon, also known as a start codon, is a specific sequence of three nucleotides that marks the beginning of a protein-coding sequence in a messenger RNA (mRNA) molecule. It serves as the starting point for the translation process, where the mRNA is read and translated into a protein by the ribosomes. The initiation codon is crucial in determining the correct reading frame and ensuring the proper synthesis of the protein.
The most commonly recognized initiation codon is AUG, which codes for the amino acid methionine in eukaryotes and bacteria, and formylmethionine in prokaryotes. In addition to AUG, alternative initiation codons such as GUG, UUG, or CUG can also be utilized, particularly in the presence of specific regulatory elements or under certain conditions. However, usage of these non-canonical start codons is generally less frequent than AUG.
Several factors contribute to the recognition of the initiation codon by the translational machinery. The small ribosomal subunit, along with other initiation factors, recognizes specific RNA sequences upstream of the initiation codon, such as the Shine-Dalgarno sequence in prokaryotes. This recognition enables the alignment of the ribosome at the correct start codon, initiating the translation process and leading to the subsequent synthesis of the protein.
In conclusion, an initiation codon is a specific RNA sequence that marks the beginning of protein synthesis in mRNA. It serves as the signal for the ribosome to commence translation and plays a vital role in determining the correct reading frame and proper protein synthesis.
Common Misspellings for INITIATION CODON
- unitiation codon
- jnitiation codon
- knitiation codon
- onitiation codon
- 9nitiation codon
- 8nitiation codon
- ibitiation codon
- imitiation codon
- ijitiation codon
- ihitiation codon
- inutiation codon
- injtiation codon
- inktiation codon
- inotiation codon
- in9tiation codon
- in8tiation codon
- iniriation codon
- inifiation codon
- inigiation codon
- iniyiation codon
Etymology of INITIATION CODON
The word "initiation codon" is derived from two distinct sources: "initiation" and "codon".
1. "Initiation" comes from the Latin word "initiatio", which means "beginning" or "entrance". It is derived from the verb "initiare", meaning "to begin". The term "initiation" refers to the process of starting or commencing something.
2. "Codon" is a term in molecular biology that refers to a specific sequence of three nucleotides (adenine, cytosine, guanine, or thymine) that codes for an amino acid or signals the termination of protein synthesis. The word "codon" is a blend of "cod" (an abbreviation for "coding") and "on" (a suffix indicating a particle or unit). The term was coined in the early 1960s when the genetic code was being deciphered.
