In order to avoid ambiguities and simplify parsing, the NCBI taxonomy identifier will be added to UniProtKB FASTA headers.

Current format:

>db|UniqueIdentifier|EntryName ProteinName OS=OrganismName [GN=GeneName ]PE=ProteinExistence SV=SequenceVersion

New format:

>db|UniqueIdentifier|EntryName ProteinName OS=OrganismName OX=OrganismIdentifier [GN=GeneName ]PE=ProteinExistence SV=SequenceVersion

Examples:

>sp|Q8I6R7|ACN2_ACAGO Acanthoscurrin-2 (Fragment) OS=Acanthoscurria gomesiana OX=115339 GN=acantho2 PE=1 SV=1
>sp|P27748|ACOX_CUPNH Acetoin catabolism protein X OS=Cupriavidus necator (strain ATCC 17699 / H16 / DSM 428 / Stanier 337) OX=381666 GN=acoX PE=4 SV=2
>sp|P04224|HA22_MOUSE H-2 class II histocompatibility antigen, E-K alpha chain OS=Mus musculus OX=10090 PE=1 SV=1

>tr|Q3SA23|Q3SA23_9HIV1 Protein Nef (Fragment) OS=Human immunodeficiency virus 1  OX=11676 GN=nef PE=3 SV=1
>tr|Q8N2H2|Q8N2H2_HUMAN cDNA FLJ90785 fis, clone THYRO1001457, moderately similar to H.sapiens protein kinase C mu OS=Homo sapiens OX=9606 PE=2 SV=1

For details please have a look at the announcement at https://www.uniprot.org/help/fasta_header_change