HTTP Services

PDB structure files, chemical component files, and several other files are available for download via http. These URLs are useful in scripted downloads using utilities such as wget.

Note: The behavior of web browsers upon using these URLs may vary. Depending on the browser configuration, some URLs may display a file in the browser (either as plain text or in a graphical viewer), and some URLs may trigger a file download to the user's computer.

Table of Contents

PDB Structure Files

PDB structure files are available in several file formats (PDB, CIF, XML), compressed or uncompressed, and with an option to download a file containing only header information (no coordinates).

Note: In addition to the download links in the table below, further links for retrieving information on any PDB structure (experimental, theoretical, unreleased, or obsolete) are available on the FAQ page.

File format Compression Example URL
PDB compressed pdb/files/4hhb.pdb.gz
PDB uncompressed pdb/files/4hhb.pdb
PDB (header only) uncompressed pdb/files/4hhb.pdb? headerOnly=YES
CIF compressed pdb/files/4hhb.cif.gz
CIF uncompressed pdb/files/4hhb.cif
CIF (header only) uncompressed pdb/files/4hhb.cif? headerOnly=YES
XML compressed pdb/files/4hhb.xml.gz
XML uncompressed pdb/files/4hhb.xml
XML (header only) uncompressed pdb/files/4hhb.xml? headerOnly=YES

Chemical Component Files

Several files are available for each chemical component. Chemical components are identified by a 3 character identifier, such as 'HEM' in the following examples.

File type File format Example URL
Definition CIF pdb/files/ligand/HEM.cif
Definition XML pdb/files/ligand/HEM.xml
Model coordinates SDF pdb/files/ligand/HEM_model.sdf
Model coordinates PDB pdb/files/ligand/HEM_model.pdb

Secondary Structure Files  

A FASTA formatted file ("ss.txt") generated using DSSP with sequences and secondary structures is available at: (compressed)

A separate file, ss_dis.txt, includes notation of regions which have not been experimentally observed, in addition to the secondary structure: (compressed)


The "Structure integration with function, taxonomy and sequence (SIFTS) initiative" aims to work towards the integration of various bioinformatics resources. SIFTS files are available for download from the RCSB PDB website using the following syntax.