DNA/RNA Codon Translator

Transcribe DNA to mRNA and translate codons into a protein chain. See the full sequence diagram with color-coded nucleotides, codon brackets, and amino acid pills. Explore the complete genetic code table or reverse-translate amino acids into all possible codons.

Input

Input Type

DNA Template Strand (3′→5′)

Enter DNA bases: A, T, G, C

Reading Frame

Presets

Sequences

DNA Template (3\u2032\u21925\u2032)

TACGGACTT

Coding Strand (5\u2032\u21923\u2032)

ATGCCTGAA

mRNA (5\u2032\u21923\u2032)

AUGCCUGAA

Protein Chain (3 amino acids)

Met\u2013Pro\u2013Glu

One-letter code

MPE

hydrophobicpolarcharged+charged-special

Open Reading Frame (ORF)

Start position

1 (base 1)

Length

9 bases (3 amino acids)

ORF sequence

AUGCCUGAA

Sequence Visualization

Reference Guide

DNA Structure

DNA is a double-stranded molecule made of four nucleotide bases. The two strands run antiparallel and are held together by hydrogen bonds between complementary base pairs.

Base pairing rules

\text{A} = \text{T} \quad (2 \text{ H-bonds}), \quad \text{G} \equiv \text{C} \quad (3 \text{ H-bonds})

The template strand (3' to 5') is read by RNA polymerase. The coding strand (5' to 3') has the same sequence as the mRNA (with T instead of U).

Transcription (DNA to RNA)

RNA polymerase reads the DNA template strand and synthesizes a complementary mRNA strand. Thymine (T) in DNA is replaced by uracil (U) in RNA.

Transcription rules

\text{A}_{\text{DNA}} \rightarrow \text{U}_{\text{RNA}}, \quad \text{T}_{\text{DNA}} \rightarrow \text{A}_{\text{RNA}}

\text{G}_{\text{DNA}} \rightarrow \text{C}_{\text{RNA}}, \quad \text{C}_{\text{DNA}} \rightarrow \text{G}_{\text{RNA}}

mRNA is synthesized in the 5' to 3' direction and carries the genetic message from the nucleus to the ribosome.

Translation (RNA to Protein)

Ribosomes read mRNA in groups of three bases called codons. Each codon specifies one amino acid. Translation begins at the start codon AUG (methionine) and ends at a stop codon.

Start and stop codons

\text{Start: AUG (Met)} \quad \text{Stop: UAA, UAG, UGA}

The reading frame determines how bases are grouped into codons. Shifting by one or two bases produces a completely different protein.

The Genetic Code

The genetic code maps 64 possible codons to 20 amino acids plus 3 stop signals. It is degenerate because most amino acids are encoded by more than one codon.

Codon degeneracy examples

\text{Leu: 6 codons} \quad \text{Met: 1 codon (AUG)} \quad \text{Trp: 1 codon (UGG)}

The code is nearly universal across all life. A few exceptions exist in mitochondria and some organisms, but the standard code applies to the vast majority of genes.