Yeast mitochondrial code explained

The yeast mitochondrial code (translation table 3) is a genetic code used by the mitochondrial genome of yeasts, notably Saccharomyces cerevisiae, Candida glabrata, Hansenula saturnus, and Kluyveromyces thermotolerans.

The code

   [[Amino acid|AAs]] = FFLLSSSSYY**CCWWTTTTPPPPHHQQRRRRIIMMTTTTNNKKSSRRVVVVAAAADDEEGGGG

[[Start codon|Starts]] = ---M---------------M---------------M---------------M------------

 [[DNA#Nucleobase_classification|Base1]] = TTTTTTTTTTTTTTTTCCCCCCCCCCCCCCCCAAAAAAAAAAAAAAAAGGGGGGGGGGGGGGGG

 Base2 = TTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGGTTTTCCCCAAAAGGGG

 Base3 = TCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAGTCAG

Bases: adenine (A), cytosine (C), guanine (G) and thymine (T) or uracil (U).

Amino acids: Alanine (Ala, A), Arginine (Arg, R), Asparagine (Asn, N), Aspartic acid (Asp, D), Cysteine (Cys, C), Glutamic acid (Glu, E), Glutamine (Gln, Q), Glycine (Gly, G), Histidine (His, H), Isoleucine (Ile, I), Leucine (Leu, L), Lysine (Lys, K), Methionine (Met, M), Phenylalanine (Phe, F), Proline (Pro, P), Serine (Ser, S), Threonine (Thr, T), Tryptophan (Trp, W), Tyrosine (Tyr, Y), Valine (Val, V).

Differences from the standard code

DNA codons	RNA codons	This code (3)		Standard code (1)
CTC	CUC	Thr (T)		Leu (L)
CTA	CUA	Thr (T)		Leu (L)
CTG	CUG	Thr (T)		Leu (L)
TGA	UGA	Trp (W)		STOP = Ter (*)
CGA	CGA	Absent		Arg (R)
CGC	CGC	Absent		Arg (R)

• The remaining CGN codons are rare in Saccharomyces cerevisiae^[1] and absent in Candida glabrata.
• The AUA codon is common in the gene var1 coding for the single mitochondrial ribosomal protein, but rare in genes encoding the enzymes.
• The coding assignments of the AUA (Met or Ile) and CUU (possibly Leu, not Thr) are uncertain in Hansenula saturnus.
• The coding assignment of Thr to CUN is uncertain in Kluyveromyces thermotolerans.

See also

• List of genetic codes

References

^[2]

Notes and References

1. Codon recognition rules in yeast mitochondria. Proc. Natl. Acad. Sci. USA. 77. 6. 3167–3170. June 1980. Susan G. Bonitz, Roberta Berlani, Gloria Coruzzi, May Li, Giuseppe Macino, Francisco G. Nobrega, Marina P. Nobrega, Arbara E. Thalenfeld and Alexander Tzagoloff. 10.1073/pnas.77.6.3167. 6997870. 349575. 1980PNAS...77.3167B. free.
2. Web site: Andrzej . Elzanowski . Jim . Ostell . Detlef . Leipe . Vladimir . Soussov . vanc . The Genetic Codes. 30 April 2015 . Taxonomy browser . National Center for Biotechnology Information (NCBI), U.S. National Library of Medicine .