DNA to mRNA & Protein Calculator
Read the strand. Follow each codon. Understand the protein.
Sequence & Strand Inputs
Transcription & Translation
mRNA SEQUENCE · 5′ → 3′
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Peptide sequence
Standard genetic code · NCBI table 1 · stop signals are not residues.
Full sequences & analysis notes
Follow the Genetic Message
All sequence rows below run 5′ → 3′. Click a codon to inspect it; use Play for one-codon steps.
Codon Inspector
Open the 64-codon reference
Standard genetic code (table 1). Select a triplet for reference lookup.
Reading Frame Comparison
* = stop, not an amino acid. Raw forward mRNA frames are shown before start/stop trimming; only the selected frame drives the main result.
Strand Logic & Assumptions
Template 3′ → 5′: complement DNA to RNA.
Coding 5′ → 3′: replace T with U.
Reverse orientation & ambiguous bases
A coding strand entered 3′ → 5′ is reversed before T→U conversion. A template entered 5′ → 3′ is reverse-complemented. Output mRNA is always 5′ → 3′. Reading frames are offsets within that mRNA, not the original pasted strand. Any N-containing triplet is conservatively X; ambiguous codons are not resolved even if all possible variants would encode one residue.
Only standard NCBI table 1 is used. AUG can encode methionine internally; an AUG alone does not prove initiation. Alternative starts, mitochondrial/other genetic codes, splicing, RNA editing and post-translational processing are not inferred. Stop signals never add an amino acid. A full-frame result containing * describes separate translation segments, not continuous protein read-through.
Sequence conversion only; no promoter prediction, splicing or RNA editing. Illustrations are conceptual and are not computed molecular structures.
Frequently asked questions
Coding or template strand?
The template is read 3′ → 5′ by RNA polymerase. The coding sequence has the same 5′ → 3′ base order as RNA, with T instead of U. Choose both role and direction to avoid a misleading complementary result.
Why do reading frames differ?
Starting at mRNA base 1, 2 or 3 changes the triplet groups. This page compares those three forward frames; it is not a six-frame ORF finder or a gene annotation pipeline.
What happens at a stop codon?
UAA, UAG and UGA are termination signals under the standard code. By default the selected translation ends at its first stop. Turning this option off displays * separators without claiming biological read-through.
What does an unknown codon mean?
N indicates an unknown DNA base. N is preserved in the RNA, and any triplet containing N is displayed as X. Invalid symbols are reported, not silently discarded. A terminal one- or two-base fragment is not translated.
Translation output is a sequence prediction, not evidence of protein expression. Sequences are processed in your browser and are not submitted to an analysis service by this tool.
Sources & References
Nucleotide-to-protein translationExPASy Translate, supported by SIBReferences identify methods; no institutional endorsement or compliance certification is claimed. SIB resource description.
Read the strand. Follow each codon. Understand the protein.