SMART: identification and annotation of domains from signalling and extracellular protein sequences

Nucleic Acids Res. 1999 Jan 1;27(1):229-32. doi: 10.1093/nar/27.1.229.


SMART is a simple modular architecture research tool and database that provides domain identification and annotation on the WWW ( The tool compares query sequences with its databases of domain sequences and multiple alignments whilst concurrently identifying compositionally biased regions such as signal peptide, transmembrane and coiled coil segments. Annotated and unannotated regions of the sequence can be used as queries in searches of sequence databases. The SMART alignment collection represents more than 250 signalling and extracellular domains. Each alignment is curated to assign appropriate domain boundaries and to ensure its quality. In addition, each domain is annotated extensively with respect to cellular localisation, species distribution, functional class, tertiary structure and functionally important residues.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Databases, Factual* / trends
  • Information Storage and Retrieval
  • Internet
  • Membrane Proteins / chemistry
  • Membrane Proteins / classification
  • Membrane Proteins / metabolism
  • Protein Sorting Signals
  • Protein Structure, Tertiary
  • Proteins / chemistry*
  • Proteins / classification
  • Proteins / metabolism*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Signal Transduction*
  • User-Computer Interface


  • Membrane Proteins
  • Protein Sorting Signals
  • Proteins