Skip to main content

Search
Visualize
Analyze
- Pairwise Structure Alignment
- Symmetry Resources in the PDB
- Structure Quality opens in a new window
- Grouping Structures
- PDB Statistics
- PDB Citation MeSH Network Explorer opens in a new window
- EPPIC Biological Assemblies opens in a new window
- External Data and Resources
- Tools at-a-glance
Download
Deposit
- Deposit via OneDep opens in a new window
- Prepare Files via pdb_extract opens in a new window
- Validate Structures opens in a new window
- PDBx/mmCIF Dictionary Resources opens in a new window
- Other Deposition Resources
About
- Contact Us
- About RCSB PDB
- Vision and Mission
- Citation, Usage, Privacy Policies, Logo
- News
- PDB History
- PDB50
- User Community
- Publications
- RCSB PDB Advisory Committee
- Team Members
- Careers
- Service Status opens in a new window
Learn

Advanced Search Sequence Search Chemical Search Browse Annotations

Advanced Search Tools

Advanced Search

Find PDB structures and Computed Structure Models (CSM) by combining queries from tools in this suite: Attribute Search, Sequence Similarity, Sequence Motif, 3D Similarity, and 3D Motif with 'AND' logic.

Sequence Similarity Search

Find structures that contain a similar nucleotide or protein sequence using the MMseqs2 method.

Chemical Search

Find small molecules by combining queries from the tools in this suite: Chemical Attributes and Chemical Similarity Search with 'AND' logic.

Browse Annotations

Find PDB structures using annotations from various ontologies and hierarchical classification schemes, e.g. Disease Ontology, Molecular Function.

Structure Summary
Structure
Annotations
Experiment
Sequence
Genome
Ligands
Versions

21OK | pdb_000021ok

FASTA Sequence
mmCIF Format
mmCIF Format (Header)
Legacy PDB Format
Legacy PDB Format (Header)
More on PDB File Formats

FASTA Sequence
PDBx/mmCIF Format
PDBx/mmCIF Format (gz)
BinaryCIF Format (gz)
Legacy PDB Format
Legacy PDB Format (gz)
More on PDB File Formats
PDBML/XML Format (gz)
Structure Factors (CIF)
Structure Factors (CIF - gz)
Validation Full (PDF - gz)
Validation (XML - gz)
Validation (CIF - gz)
Validation 2fo-fc coefficients (CIF - gz)
Validation fo-fc coefficients (CIF - gz)
Biological Assembly 1 (CIF - gz)

A1A2Y
EDO
HEM
CYN
NA

NA: SODIUM ION

No ligand validation data is available for NA

Follow us:

Partnerships & Collaborators:

PDB-101

wwPDB

EMDataResource

wwPDB Foundation

About
About Us
Citing Us
Publications
Team
Careers
Usage & Privacy

Support
Contact Us
Help
Website FAQ
Glossary
Service Status

RCSB PDB is hosted by

RCSB PDB is a member of

RCSB Partners
Nucleic Acid Knowledgebase

wwPDB Partners
RCSB PDB
PDBe
PDBj
BMRB
EMDB
PDBc

CoreTrustSeal

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729. RCSB PDB uses resources of the National Energy Research Scientific Computing Center (NERSC), a Department of Energy User Facility.