Entrez is a search and retrieval system that integrates information from databases at the National Center for Biotechnology Information (NCBI). You can easily search it using keywords. Just select the database and then enter the keywords and then click Go. An example page is given below, searching GenBank for Cystic fibrosis sequences.
These databases include:
- nucleotide sequences - GenBank
- protein sequences - SwissProt, PIR, PRF, PDB
- macromolecular structures - The Molecular Modelling (MMDB) and Brookhaven Protein Database (PDB) contain three-dimensional structures of proteins and other macromolecules.
- journal articles - PubMed (MEDLINE) and On-line Medelian Inheritance in Man (OMIM), a catalog of human genes and genetic disorders.
- whole genomes - The whole genomes of over 800 organisms can be found in Entrez Genomes.
- taxonomy - The NCBI taxonomy database contains the names of all organisms that are represented in the genetic databases with at least one nucleotide or protein sequence