NCBI Protein Domains and Macromolecular Structures

  Conserved domain hierarchy showing divergence in a protein family based on phylogenetic relationships of protein sequences and functional properties. Click on the image for a more detailed illustration and additional information about domain family hierarchies.   Conserved domains and protein classification
 
Conserved domains are functional units within a protein that act as building blocks in molecular evolution and recombine in various arrangements to make proteins with different functions. The Conserved Domain Database (CDD) brings together several collections of multiple sequence alignments representing conserved domains, in addition to NCBI-curated domains that use 3D-structure information explicitly to define domain boundaries and provide insights into sequence/structure/function relationships...expand paragraph
 
 

 

  Example 3-dimensional structure: Tumor Suppressor P53 Complexed with DNA (accession 1TUP). Click on the image for more information about the structure and for examples of how 3D structures can be used to learn more about proteins and other biomolecules.   Macromolecular structures
 
The three-dimensional structures of biomolecules provide a wealth of information on their biological function and evolutionary relationships. The Molecular Modeling Database (MMDB), as part of the Entrez system, facilitates access to structure data by connecting them with associated literature, protein and nucleic acid sequences, chemicals, biomolecular interactions, and more. It is possible, for example, to find 3D structures for homologs of a protein of interest by following the "Related Structures" link in an Entrez Protein sequence record...expand paragraph