text: user4794: I have a protein Seq. and I want to know
  
  how to Know the longest ORF in this Protein?
  
  and if there is any tutorial for this process ?? 
  
  user2436: Proteins don't have ORFs, DNA sequences do.  What DNA sequences do you have?  If cDNA (i.e. transcript/mRNA) then an ORF finder will give multiple ORFs and the coordinates on the full-length input DNA which indicate it's length.
  
original_text: 4794: <p>I have a protein Seq. and I want to know</p>
  
  <ul>
  <li>how to Know the longest ORF in this Protein?</li>
  </ul>
  
  <p>and if there is any tutorial for this process ?? </p>
   2436: <p>Proteins don't have ORFs, DNA sequences do.  What DNA sequences do you have?  If cDNA (i.e. transcript/mRNA) then an ORF finder will give multiple ORFs and the coordinates on the full-length input DNA which indicate it's length.</p>
  