text: user12036: I was playing around, looking at some AlphaFold predictions for certain proteins and I realized that sometimes the sequences of aminoacid look very different for the same UniProt id. For example, 15C8 from PDB has 2 chains:
  DIVLTQSPAIMSASLGERVTMTCTASSSVSSSNLHWYQQKPGSSPKLWIYSTSNLA
  SGVPARFSGSGSGTSYSLTISSMEAEDAATYYCHQYHRSPYTFGGGTKLEIKRADA
  APTVSIFPPSSEQLTSGGASVVCFLNNFYPKDINVKWKIDGSERQNGVLNSWTDQD
  SKDSTYSMSSTLTLTKDEYERHNSYTCEATHKTSTSPIVKSFNRN
  
  and
  EVQLQQSGAELVKPGASVKLSCTASGFNIKDTYMHWVKQKPEQGLEWIAQIDPANG
  NTKYDPKFQGKATITADTSSNTAYLHLSSLTSEDSAVYYCAADPPYYGHGDYWGQG
  TTLTVSSAKTTPPSVYPLAPGSAAQTNSMVTLGCLVKGYFPEPVTVTWNSGSLSSG
  VHTFPAVLQSDLYTLSSSVTVPSSTWPSETVTCNVAHPASSTKVDKKIV
  
  At the same time, when looking at the UniProt database (the corresponding id is P01869), there's a list of multiple structures and their 3D shapes (here: https://www.uniprot.org/uniprot/P01869). However, looking at the AlphaFold entry, I see that the amino acid sequence looks different, eg. for the case above it's:
  AKTTPPSVYPLAPGSAAQTNSMVTLGCLVKGYFPEPVTVTWNSGSLSSGVHTFPAV
  LQSDLYTLSSSVTVPSSPRPSETVTCNVAHPASSTKVDKKIVPRDCGCKPCICTVP
  EVSSVFIFPPKPKDVLTITLTPKVTCVVVDISKDDPEVQFSWFVDDVEVHTAQTQP
  REEQFNSTFRSVSELPIMHQDWLNGKEFKCRVNSAAFPAPIEKTISKTKGRPKAPQ
  VYTIPPPKEQMAKDKVSLTCMITDFFPEDITVEWQWNGQPAENYKNTQPIMNTNGS
  YFVYSKLNVQKSNWEAGNTFTCSVLHEGLHNHHTEKSLSHSPGLQLDETCAEAQDG
  ELDGLWTTITIFISLFLLSVCYSAAVTLFKVKWIFSSVVELKQTLVPEYKNMIGQA
  P
  
  My question (as someone who's just getting started with proteins) would be: what is the relationship between all these entries corresponding to the same UniProt Id?
  
  user298: PDB structure 15C8 corresponds to the protein product of the mouse Igkc gene, with the UniProt accession P01837 as you can see in the linked page:
  
  Your P01869 UniProt accession is for the protein product of the mouse Ighg1 gene instead, so why would you expect these to be the same sequence? They are different proteins coded for by different genes.
  
original_text: 12036: <p>I was playing around, looking at some AlphaFold predictions for certain proteins and I realized that sometimes the sequences of aminoacid look very different for the same UniProt id. For example, 15C8 from PDB has 2 chains:</p>
  <pre><code>DIVLTQSPAIMSASLGERVTMTCTASSSVSSSNLHWYQQKPGSSPKLWIYSTSNLA
  SGVPARFSGSGSGTSYSLTISSMEAEDAATYYCHQYHRSPYTFGGGTKLEIKRADA
  APTVSIFPPSSEQLTSGGASVVCFLNNFYPKDINVKWKIDGSERQNGVLNSWTDQD
  SKDSTYSMSSTLTLTKDEYERHNSYTCEATHKTSTSPIVKSFNRN
  </code></pre>
  <p>and</p>
  <pre><code>EVQLQQSGAELVKPGASVKLSCTASGFNIKDTYMHWVKQKPEQGLEWIAQIDPANG
  NTKYDPKFQGKATITADTSSNTAYLHLSSLTSEDSAVYYCAADPPYYGHGDYWGQG
  TTLTVSSAKTTPPSVYPLAPGSAAQTNSMVTLGCLVKGYFPEPVTVTWNSGSLSSG
  VHTFPAVLQSDLYTLSSSVTVPSSTWPSETVTCNVAHPASSTKVDKKIV
  </code></pre>
  <p>At the same time, when looking at the UniProt database (the corresponding id is P01869), there's a list of multiple structures and their 3D shapes (here: <a href="https://www.uniprot.org/uniprot/P01869" rel="nofollow noreferrer">https://www.uniprot.org/uniprot/P01869</a>). However, looking at the AlphaFold entry, I see that the amino acid sequence looks different, eg. for the case above it's:</p>
  <pre><code>AKTTPPSVYPLAPGSAAQTNSMVTLGCLVKGYFPEPVTVTWNSGSLSSGVHTFPAV
  LQSDLYTLSSSVTVPSSPRPSETVTCNVAHPASSTKVDKKIVPRDCGCKPCICTVP
  EVSSVFIFPPKPKDVLTITLTPKVTCVVVDISKDDPEVQFSWFVDDVEVHTAQTQP
  REEQFNSTFRSVSELPIMHQDWLNGKEFKCRVNSAAFPAPIEKTISKTKGRPKAPQ
  VYTIPPPKEQMAKDKVSLTCMITDFFPEDITVEWQWNGQPAENYKNTQPIMNTNGS
  YFVYSKLNVQKSNWEAGNTFTCSVLHEGLHNHHTEKSLSHSPGLQLDETCAEAQDG
  ELDGLWTTITIFISLFLLSVCYSAAVTLFKVKWIFSSVVELKQTLVPEYKNMIGQA
  P
  </code></pre>
  <p>My question (as someone who's just getting started with proteins) would be: what is the relationship between all these entries corresponding to the same UniProt Id?</p>
   298: <p><a href="https://www.rcsb.org/structure/15C8" rel="nofollow noreferrer">PDB structure 15C8</a> corresponds to the protein product of the mouse <em>Igkc</em> gene, with the UniProt accession <a href="https://www.uniprot.org/uniprot/P01837" rel="nofollow noreferrer">P01837</a> as you can see in the linked page:</p>
  <p><a href="https://i.stack.imgur.com/rfTlX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rfTlX.png" alt="screenshot of PDB entry 15C8" /></a></p>
  <p>Your <a href="https://www.uniprot.org/uniprot/P01869" rel="nofollow noreferrer">P01869</a> UniProt accession is for the protein product of the mouse <em>Ighg1</em> gene instead, so why would you expect these to be the same sequence? They are different proteins coded for by different genes.</p>
  