text: user12272: Some websites mention amino acid mutations as ORF1ab, most however use ORF1a/b instead.
  So how can I translate from one to the other? What do I need to subtract from say ORF1ab:4588I to get the corresponding N in ORF1b:<N>I?
  
  user12272: ORF1ab:4588I corresponds to ORF1b:187I so one needs to subtract 4401 to go from 1ab to 1b and add 4401 to go the other way.
  
  user14239: There is now an Open Source online tool that does the conversion, Codon2Nucleotide by Theo Sanderson.
  
original_text: 12272: <p>Some websites mention amino acid mutations as ORF1ab, most however use ORF1a/b instead.</p>
  <p>So how can I translate from one to the other? What do I need to subtract from say <code>ORF1ab:4588I</code> to get the corresponding <code>N</code> in <code>ORF1b:&lt;N&gt;I</code>?</p>
   12272: <p><code>ORF1ab:4588I</code> corresponds to <code>ORF1b:187I</code> so one needs to subtract <code>4401</code> to go from <code>1ab</code> to <code>1b</code> and add <code>4401</code> to go the other way.</p>
   14239: <p>There is now an Open Source online tool that does the conversion, <a href="https://codon2nucleotide.theo.io/" rel="nofollow noreferrer">Codon2Nucleotide</a> by Theo Sanderson.</p>
  