Multiple UniProt IDs for a PDB

Question

[tims0073]

Hi,

I found that some PDBs have multiple UNIProt IDs assigned to it. Any idea why this happens and what it means?

For example see this:

https://www.rcsb.org/pdb/rest/das/pdb_uniprot_mapping/alignment?query=3MMP.A (P0A6P1 and P0CE48) https://www.rcsb.org/pdb/rest/das/pdb_uniprot_mapping/alignment?query=3J9P.B (P0AEX9 and O75762)

What does the block blockOrder mean here?

Thanks, tim

[GenoMax]

While the following could be an explanation

Each chain in a protein complex, corresponding to said PDB accession number, may have a different Uniprot accession number

it does not seem to apply in the case you have noted (3J9P). It does not appear to have any logical links either since one is a human protein and other an E coli one.