AnticodonCodonInteraktionsbereich

Anticodon and codon are fundamental elements of the genetic code during protein synthesis. A codon is a sequence of three nucleotides in messenger RNA that specifies a particular amino acid or a stop signal. An anticodon is a complementary triplet of nucleotides located in the anticodon loop of transfer RNA, which recognizes a codon through base pairing as the ribosome translates the mRNA.

Typically, codon–anticodon pairing follows standard Watson-Crick rules, with G-C and A-U (or A-U in RNA); several tRNAs can pair with multiple codons due to wobble base pairing at the third codon position, allowing redundancy in the genetic code. This wobble flexibility explains why there are fewer tRNA species than codons for many amino acids. The aminoacyl-tRNA synthetases charge each tRNA with the correct amino acid; the anticodon acts as a key recognition element during translation.

Errors in codon–anticodon pairing can lead to misincorporation of amino acids, which may affect protein function. Cells mitigate errors via kinetic proofreading and quality control checks in translation. Anticodons may contain modified nucleotides that expand pairing possibilities or improve fidelity. Codon usage bias and tRNA abundance influence translation efficiency and gene expression.

In certain organelles and some organisms, genetic code variations exist, altering specific codon meanings; nonetheless, the basic anticodon–codon pairing mechanism remains central to decoding mRNA into proteins.