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Prints By Albrecht Dürer
In molecular biology, the PRINTS database is a collection of so-called "fingerprints": it provides both a detailed annotation resource for protein families, and a diagnostic tool for newly determined sequences. A fingerprint is a group of conserved motifs taken from a multiple sequence alignment - together, the motifs form a characteristic signature for the aligned protein family. The motifs themselves are not necessarily contiguous in sequence, but may come together in 3D space to define molecular binding sites or interaction surfaces. The particular diagnostic strength of fingerprints lies in their ability to distinguish sequence differences at the clan, superfamily, family and subfamily levels. This allows fine-grained functional diagnoses of uncharacterised sequences, allowing, for example, discrimination between family members on the basis of the ligands they bind or the proteins with which they interact, and highlighting potential oligomerisation or allosteric sites. PRINTS i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Family
A protein family is a group of evolutionarily related proteins. In many cases, a protein family has a corresponding gene family, in which each gene encodes a corresponding protein with a 1:1 relationship. The term "protein family" should not be confused with family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar three-dimensional structures, functions, and significant sequence similarity. Sequence similarity (usually amino-acid sequence) is one of the most common indicators of homology, or common evolutionary ancestry. Some frameworks for evaluating the significance of similarity between sequences use sequence alignment methods. Proteins that do not share a common ancestor are unlikely to show statistically significant sequence similarity, making sequence alignment a powerful tool for identifying the members of protein families. Families are sometimes grouped together into larger clades called superfamilies based on st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence Motif
In biology, a sequence motif is a nucleotide or amino-acid sequence pattern that is widespread and usually assumed to be related to biological function of the macromolecule. For example, an ''N''-glycosylation site motif can be defined as ''Asn, followed by anything but Pro, followed by either Ser or Thr, followed by anything but Pro residue''. Overview When a sequence motif appears in the exon of a gene, it may encode the " structural motif" of a protein; that is a stereotypical element of the overall structure of the protein. Nevertheless, motifs need not be associated with a distinctive secondary structure. " Noncoding" sequences are not translated into proteins, and nucleic acids with such motifs need not deviate from the typical shape (e.g. the "B-form" DNA double helix). Outside of gene exons, there exist regulatory sequence motifs and motifs within the " junk", such as satellite DNA. Some of these are believed to affect the shape of nucleic acids (see for example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Sequence Alignment
Multiple sequence alignment (MSA) is the process or the result of sequence alignment of three or more biological sequences, generally protein, DNA, or RNA. These alignments are used to infer evolutionary relationships via phylogenetic analysis and can highlight homologous features between sequences. Alignments highlight mutation events such as point mutations (single amino acid or nucleotide changes), insertion mutations and deletion mutations, and alignments are used to assess sequence conservation and infer the presence and activity of protein domains, tertiary structures, secondary structures, and individual amino acids or nucleotides. Multiple sequence alignments require more sophisticated methodologies than pairwise alignments, as they are more computationally complex. Most multiple sequence alignment programs use heuristic methods rather than global optimization because identifying the optimal alignment between more than a few sequences of moderate length is prohibiti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
InterPro
InterPro is a database of protein families, protein domains and functional sites in which identifiable features found in known proteins can be applied to new protein sequences in order to functionally characterise them. The contents of InterPro consist of diagnostic signatures and the proteins that they significantly match. The signatures consist of models (simple types, such as regular expressions or more complex ones, such as Hidden Markov models) which describe protein families, domains or sites. Unknown sequences are searched to create homology models. Each of the member databases of InterPro contributes towards a different niche, from very high-level, structure-based classifications ( SUPERFAMILY and CATH-Gene3D) through to quite specific sub-family classifications ( PRINTS and PANTHER). InterPro's intention is to provide a one-stop-shop for protein classification, where all the signatures produced by the different member databases are placed into entries within the Inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Databases
Biological databases are libraries of biological sciences, collected from scientific experiments, published literature, high-throughput experiment technology, and computational analysis. They contain information from research areas including genomics, proteomics, metabolomics, microarray gene expression, and phylogenetics. Information contained in biological databases includes gene function, structure, localization (both cellular and chromosomal), clinical effects of mutations as well as similarities of biological sequences and structures. Biological databases can be classified by the kind of data they collect (see below). Broadly, there are molecular databases (for sequences, molecules, etc.), functional databases (for physiology, enzyme activities, phenotypes, ecology etc), taxonomic databases (for species and other taxonomic ranks), images and other media, or specimens (for museum collections etc.) Databases are important tools in assisting scientists to analyze and explain a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
