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ABCdb
ABCdb is a biological database for the adenosine triphosphate-binding cassette (ABC) transporters encoded by completely sequenced archaeal and bacterial genomes. These proteins are important for transporting substances into cells and are found in all living organisms. biological function of ABC systems Most ABC systems function in the transport of a compound across a membrane into the cell (importer) or to the exterior (exporter), for which the system generates energy by the hydrolysis of adenosine triphosphate (ATP). The ABC transporters occur in all living organisms. An ABC transporter system consist minimally of two components: an ATP binding cassette and a transmembrane domain or membrane spanning domain. These are usually separate proteins or can occur as protein domains. A typical ABC transporter is composed of two nucleotide binding domains that energize transport via ATP hydrolysis and of two membrane spanning domains that act as a membrane channel for the substrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATP-binding Cassette Transporter
The ATP-binding cassette transporters (ABC transporters) are a transport system superfamily that is one of the largest and possibly one of the oldest gene families. It is represented in all extant phyla, from prokaryotes to humans. ABC transporters belong to translocases. ABC transporters often consist of multiple subunits, one or two of which are transmembrane proteins and one or two of which are membrane-associated AAA ATPases. The ATPase subunits utilize the energy of adenosine triphosphate (ATP) binding and hydrolysis to provide the energy needed for the translocation of substrates across membranes, either for uptake or for export of the substrate. Most of the uptake systems also have an extracytoplasmic receptor, a solute binding protein. Some homologous ATPases function in non-transport-related processes such as translation of RNA and DNA repair. ABC transporters are considered to be an ABC superfamily based on the similarities of the sequence and organization of thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABC Transporters
The ATP-binding cassette transporters (ABC transporters) are a transport system superfamily that is one of the largest and possibly one of the oldest gene families. It is represented in all extant phyla, from prokaryotes to humans. ABC transporters belong to translocases. ABC transporters often consist of multiple subunits, one or two of which are transmembrane proteins and one or two of which are membrane-associated AAA ATPases. The ATPase subunits utilize the energy of adenosine triphosphate (ATP) binding and hydrolysis to provide the energy needed for the translocation of substrates across membranes, either for uptake or for export of the substrate. Most of the uptake systems also have an extracytoplasmic receptor, a solute binding protein. Some homologous ATPases function in non-transport-related processes such as translation of RNA and DNA repair. ABC transporters are considered to be an ABC superfamily based on the similarities of the sequence and organization of their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Domain Of ABC Transporters
ABC transporter transmembrane domain is the main transmembrane structural unit of ATP-binding cassette transporter proteins, consisting of six alpha helixes that traverse the plasma membrane. Many members of the ABC transporter family () have two such regions. This family appears to correspond to ABC1 by TCDB classification. Subfamilies * Sulphate ABC transporter permease protein 2 * Phosphate transport system permease protein 2 *Phosphonate uptake transporter * Nitrate transport permease * NifC-like ABC-type porter *Phosphate ABC transporter, permease protein PstC *Molybdate ABC transporter, permease protein *Nickel ABC transporter, permease subunit NikB *Nickel ABC transporter, permease subunit NikC * Ectoine/hydroxyectoine ABC transporter, permease protein EhuD * Ectoine/hydroxyectoine ABC transporter, permease protein EhuC Human proteins containing this domain ABCB1; ABCB10; ABCB11; ABCB4; ABCB5; ABCB6; ABCB7; ABCB8; ABCB9; ABCC1; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Domain Resource
The public domain (PD) consists of all the creative work to which no exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly waived, or may be inapplicable. Because those rights have expired, anyone can legally use or reference those works without permission. As examples, the works of William Shakespeare, Ludwig van Beethoven, Leonardo da Vinci and Georges Méliès are in the public domain either by virtue of their having been created before copyright existed, or by their copyright term having expired. Some works are not covered by a country's copyright laws, and are therefore in the public domain; for example, in the United States, items excluded from copyright include the formulae of Newtonian physics, cooking recipes,Copyright Protection Not A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequence Analysis
In bioinformatics, sequence analysis is the process of subjecting a DNA, RNA or peptide sequence to any of a wide range of analytical methods to understand its features, function, structure, or evolution. Methodologies used include sequence alignment, searches against biological databases, and others. Since the development of methods of high-throughput production of gene and protein sequences, the rate of addition of new sequences to the databases increased very rapidly. Such a collection of sequences does not, by itself, increase the scientist's understanding of the biology of organisms. However, comparing these new sequences to those with known functions is a key way of understanding the biology of an organism from which the new sequence comes. Thus, sequence analysis can be used to assign function to genes and proteins by the study of the similarities between the compared sequences. Nowadays, there are many tools and techniques that provide the sequence comparisons (sequence a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paralog
Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a speciation event (orthologs), or a duplication event (paralogs), or else a horizontal (or lateral) gene transfer event (xenologs). Homology among DNA, RNA, or proteins is typically inferred from their nucleotide or amino acid sequence similarity. Significant similarity is strong evidence that two sequences are related by evolutionary changes from a common ancestral sequence. Alignments of multiple sequences are used to indicate which regions of each sequence are homologous. Identity, similarity, and conservation The term "percent homology" is often used to mean "sequence similarity”, that is the percentage of identical residues (''percent identity''), or the percentage of residues conserved with similar physicochemical properties ( ... [...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. 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 powerful tool for identifying the members of protein families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Domain
In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of several domains, and a domain may appear in a variety of different proteins. Molecular evolution uses domains as building blocks and these may be recombined in different arrangements to create proteins with different functions. In general, domains vary in length from between about 50 amino acids up to 250 amino acids in length. The shortest domains, such as zinc fingers, are stabilized by metal ions or disulfide bridges. Domains often form functional units, such as the calcium-binding EF hand domain of calmodulin. Because they are independently stable, domains can be "swapped" by genetic engineering between one protein and another to make chimeric proteins. Background The concept of the domain was first proposed in 1973 by Wetlaufe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid resid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATP-binding Domain Of ABC Transporters
In molecular biology, ATP-binding domain of ABC transporters is a water-soluble domain of transmembrane ABC transporters. ABC transporters belong to the ATP-Binding Cassette superfamily, which uses the hydrolysis of ATP to translocate a variety of compounds across biological membranes. ABC transporters are minimally constituted of two conserved regions: a highly conserved ATP binding cassette (ABC) and a less conserved transmembrane domain (TMD). These regions can be found on the same protein or on two different ones. Most ABC transporters function as a dimer and therefore are constituted of four domains, two ABC modules and two TMDs. Biological function ABC transporters are involved in the export or import of a wide variety of substrates ranging from small ions to macromolecules. The major function of ABC import systems is to provide essential nutrients to bacteria. They are found only in prokaryotes and their four constitutive domains are usually encoded by independent pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
