Content deleted Content added
minor edit |
Corrected start codons in Table1. |
||
Line 32:
UUC [[Phenylalanine]]<br>
UUA [[Leucine]]<br>
UUG [[Leucine]], ''Start''<br>
</td>
<td>
Line 60:
CUC [[Leucine]]<br>
CUA [[Leucine]]<br>
CUG [[Leucine]], ''Start''<br>
</td>
<td>
Line 85:
<th>A</th>
<td>
AUU [[Isoleucine]], ''Start''<sup>2</sup><br>
AUC [[Isoleucine]]<br>
AUA [[Isoleucine]]<br>
AUG [[Methionine]], ''Start''
</td>
<td>
Line 116:
GUC [[Valine]]<br>
GUA [[Valine]]<br>
GUG [[Valine]], ''Start''<sup>2</sup><br>
</td>
<td>
Line 141:
<center>
<sup>1</sup>The codon AUG both codes for methionine and serves as an initiation site: the first AUG in an [[mRNA]]'s coding region is where translation into protein begins.
<br>
<sup>2</sup>This is a start codon for [[prokaryotes]].
</center>
Line 216 ⟶ 218:
</table>
<br>
In classical genetics, the stop codons were given names - UAG was amber, UGA was opal, and UAA was ocher. These names were originally the names of the specific genes in which mutation of each of these stop codons was first detected. Translation starts with a chain initiation codon (start codon). But unlike stop codons, these are not sufficient to begin the process; nearby initiation sequences are also required to induce transcription into mRNA and binding by [[ribosome]]s. The most notable start codon is AUG, which also codes for methionine. CUG and UUG, and in [[prokaryotes]] GUG and AUU, also work.
It is notable that the standard genetic code contains features of basic [[error correction]]. Many codons which differ by only one base codes for the same amino acid, and most often the base that differs is the last base, which happens to be the base which is most often misread in the translation process. Furthermore, amino acids which tend to occur more frequently in proteins on average tend to have more codons which code for them.
| |||