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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 ... [...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 (biology), family as it is used in taxonomy. Proteins in a family descend from a common ancestor and typically have similar protein structure, three-dimensional structures, functions, and significant Sequence homology, sequence similarity. The most important of these is sequence similarity (usually amino-acid sequence), since it is the strictest indicator of homology and therefore the clearest indicator of common ancestry. A fairly well developed framework exists for evaluating the significance of similarity between a group of sequences using sequence alignment methods. Proteins that do not share a common ancestor are very unlikely to show statistically significant sequence similarity, making sequence alignment a powerf ... [...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 RN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Sequence Alignment
Multiple sequence alignment (MSA) may refer to the process or the result of sequence alignment of three or more biological sequences, generally protein, DNA, or RNA. In many cases, the input set of query sequences are assumed to have an evolutionary relationship by which they share a linkage and are descended from a common ancestor. From the resulting MSA, sequence homology can be inferred and phylogenetic analysis can be conducted to assess the sequences' shared evolutionary origins. Visual depictions of the alignment as in the image at right illustrate mutation events such as point mutations (single amino acid or nucleotide changes) that appear as differing characters in a single alignment column, and insertion or deletion mutations (indels or gaps) that appear as hyphens in one or more of the sequences in the alignment. Multiple sequence alignment is often used to assess sequence conservation of protein domains, tertiary and secondary structures, and even individual amino acid ... [...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. Models are built from the amino acid sequences of known families or domains and they are subsequently used to search unknown sequences (such as those arising from novel genome sequencing) in order to classify them. 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 pro ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
