Single sequence – NCBI BLAST

Start from one protein sequence or protein structure. Uploading or fetching a PDB/mmCIF structure is recommended because the selected chain can be carried forward as the analysis reference and mapped directly onto the structure after alignment and tree construction.

Upload query file

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Fetch a query sequence

Enter an NCBI protein accession or PDB identifier.

or enter the query

Required for NCBI sequence retrieval and identification of programmatic requests.

Provide one protein sequence or structure file, or fetch a query by NCBI/PDB identifier.
BLAST parameters
Low-complexity filter
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Adjust short queries
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ClusteredNR is submitted to NCBI using the database identifier nr_cluster_seq and is recommended for interactive homolog retrieval. The full nr database can take substantially longer, especially through the programmatic queue.