Translate DNA to protein
Paste DNA, mRNA or FASTA. Pick the frame, strand and genetic code.
Paste DNA, mRNA or FASTA. Pick the frame, strand and genetic code.
A ribosome reads messenger RNA three bases at a time. Each triplet, a codon, specifies one amino acid, and the chain of amino acids is the protein. This tool does the same thing to a DNA or RNA sequence: it takes the bases in groups of three from the chosen starting position, looks each codon up in the genetic code, and writes out the amino acid sequence. Stop codons are shown as *, methionine, the usual start, as M. Any bases left over at the end that do not make a full codon are dropped and counted in the summary.
Because codons are three bases long, a sequence can be read starting at base 1, 2 or 3, and each gives a different protein. Those are the three forward reading frames. The complementary strand, read in its own 5′→3′ direction, adds three more, so every DNA sequence has six reading frames. Only one of them is the real protein for a given gene. If you know your sequence starts at the ATG, use frame 1 on the forward strand. If you do not, the six-frame translation shows all six at once and theORF finder picks out the long stop-free stretches automatically. The reverse complement tool gives you the other strand on its own.
Rows are the first base of the codon, columns the second, and the four entries in each cell run through T, C, A, G as the third base. Sixty-one codons encode the twenty amino acids and three, TAA, TAG and TGA, are stops. The code is degenerate: most amino acids have several codons, differing mostly in the third position, which is why a third-position ambiguity such as GCN still translates to a single amino acid.
| T | C | A | G | |
|---|---|---|---|---|
| T | TTTPhe TTCPhe TTALeu TTGLeu | TCTSer TCCSer TCASer TCGSer | TATTyr TACTyr TAAStop TAGStop | TGTCys TGCCys TGAStop TGGTrp |
| C | CTTLeu CTCLeu CTALeu CTGLeu | CCTPro CCCPro CCAPro CCGPro | CATHis CACHis CAAGln CAGGln | CGTArg CGCArg CGAArg CGGArg |
| A | ATTIle ATCIle ATAIle ATGMet | ACTThr ACCThr ACAThr ACGThr | AATAsn AACAsn AAALys AAGLys | AGTSer AGCSer AGAArg AGGArg |
| G | GTTVal GTCVal GTAVal GTGVal | GCTAla GCCAla GCAAla GCGAla | GATAsp GACAsp GAAGlu GAGGlu | GGTGly GGCGly GGAGly GGGGly |
The standard code is used by nuclear genes of almost every organism and by bacteria, but mitochondria, plastids and a few nuclear lineages reassign codons. Vertebrate mitochondria read TGA as tryptophan instead of stop, ATA as methionine, and AGA and AGG as stops. Ciliates read TAA and TAG as glutamine. The genetic code menu follows the NCBI numbering, so table 2 here is the same table 2 that BLAST, GenBank and Biopython use. Table 11, for bacteria and plastids, translates identically to the standard code; it differs only in which codons can start a gene.
IUPAC ambiguity codes are resolved codon by codon. If every base the code could stand for gives the same amino acid, that amino acid is written; GCN is alanine and CCY is proline. If the possibilities disagree, or the codon contains a character that is not a base, the output showsX. U is read as T, so an mRNA sequence translates directly. Whitespace, line breaks and the digits of GenBank-style numbering are ignored, and each record of a multi-record FASTA file is translated separately under its own header.
The one-letter code is what sequence databases and alignment tools use, and it is the default here. Switch to three-letter output for a figure or a lab notebook, where Met-Val-Ser reads more easily than MVS. To convert an existing protein sequence between the two, use theone-letter to three-letter converter.
Paste the coding sequence, choose the reading frame that starts at the first base of a codon (frame 1 if the sequence begins with ATG) and read the amino acids. Each group of three bases is one codon and encodes one amino acid according to the genetic code; TAA, TAG and TGA end the protein.
If your sequence starts at the ATG of a coding sequence, frame 1. If you do not know where the gene starts, translate all six frames and pick the one with a long stretch free of stop codons, or use the ORF finder, which does exactly that.
Almost always because the sequence is being read in the wrong frame or on the wrong strand. A real coding region has no internal stops, so a translation full of asterisks means the frame is off by one or two bases, or the gene runs on the reverse strand.
A codon that could not be resolved to a single amino acid: it contains an ambiguity code such as N, or a character that is not a base. Codons with an ambiguity that does not change the amino acid, such as GCN for alanine, are translated normally.
Yes. U is read as T, so mRNA translates directly. Mitochondrial, ciliate and other variant genetic codes are available in the genetic code menu; vertebrate mitochondria, for example, read TGA as tryptophan and AGA and AGG as stops.