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BTB Domain
The BTB/POZ domain is a common structural domain contained within some proteins. The BTB (for BR-C, ttk and bab) or POZ (for Pox virus and Zinc finger) domain is present near the N-terminus of a fraction of zinc finger proteins and in proteins that contain the Kelch motif and a family of pox virus proteins. The BTB/POZ domain mediates homomeric dimerisation and in some instances heteromeric dimerisation. The structure of the dimerised PLZF BTB/POZ domain has been solved and consists of a tightly intertwined homodimer. The central scaffolding of the protein is made up of a cluster of alpha-helices flanked by short beta-sheets at both the top and bottom of the molecule. BTB/POZ domains from several zinc finger proteins have been shown to mediate transcriptional repression and to interact with components of histone deacetylase Histone deacetylases (, HDAC) are a class of enzymes that remove acetyl groups (O=C-CH3) from an ε-N-acetyl lysine amino acid on a histone, allowing the hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural 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 Wetlaufer after ... [...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 residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-terminus
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amine group is bonded to the carboxylic group of another amino acid, making it a chain. That leaves a free carboxylic group at one end of the peptide, called the C-terminus, and a free amine group on the other end called the N-terminus. By convention, peptide sequences are written N-terminus to C-terminus, left to right (in LTR writing systems). This correlates the translation direction to the text direction, because when a protein is translated from messenger RNA, it is created from the N-terminus to the C-terminus, as amino acids are added to the carboxyl end of the protein. Chemistry Each amino acid has an amine group and a carboxylic group. Amino acids link to one another by peptide bonds which form through a dehydration reaction that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Finger
A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions (Zn2+) in order to stabilize the fold. It was originally coined to describe the finger-like appearance of a hypothesized structure from the African clawed frog (''Xenopus laevis'') transcription factor IIIA. However, it has been found to encompass a wide variety of differing protein structures in eukaryotic cells. ''Xenopus laevis'' TFIIIA was originally demonstrated to contain zinc and require the metal for function in 1983, the first such reported zinc requirement for a gene regulatory protein followed soon thereafter by the Krüppel factor in ''Drosophila''. It often appears as a metal-binding domain in multi-domain proteins. Proteins that contain zinc fingers (zinc finger proteins) are classified into several different structural families. Unlike many other clearly defined supersecondary structures such as Greek keys or β hairpins, there are a number of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelch Motif
The Kelch motif is a region of protein sequence found widely in proteins from bacteria and eukaryotes. This sequence motif is composed of about 50 amino acid residues which form a structure of a four stranded beta-sheet "blade". This sequence motif is found in between five and eight tandem copies per protein which fold together to form a larger circular solenoid structure called a beta-propeller domain. Proteins containing Kelch motifs The Kelch motif is widely found in eukaryotic and bacterial species. Notably the human genome contains around 100 proteins containing the Kelch motif. Within individual proteins the motif occurs multiple times. For example, the motif appears 6 times in ''Drosophila'' egg-chamber regulatory protein. The motif is also found in mouse protein MIPP and in a number of poxviruses. In addition, kelch repeats have been recognised in alpha- and beta-scruin, in galactose oxidase from the fungus '' Dactylium dendroides'' and in the ''Escherichia co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histone Deacetylase
Histone deacetylases (, HDAC) are a class of enzymes that remove acetyl groups (O=C-CH3) from an ε-N-acetyl lysine amino acid on a histone, allowing the histones to wrap the DNA more tightly. This is important because DNA is wrapped around histones, and DNA expression is regulated by acetylation and de-acetylation. Its action is opposite to that of histone acetyltransferase. HDAC proteins are now also called lysine deacetylases (KDAC), to describe their function rather than their target, which also includes non-histone proteins. HDAC super family Together with the acetylpolyamine amidohydrolases and the acetoin utilization proteins, the histone deacetylases form an ancient protein superfamily known as the histone deacetylase superfamily. Classes of HDACs in higher eukaryotes HDACs, are classified in four classes depending on sequence homology to the yeast original enzymes and domain organization: HDAC (except class III) contain zinc and are known as Zn2+-dependent hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Receptor Co-repressor 1
The nuclear receptor co-repressor 1 also known as thyroid-hormone- and retinoic-acid-receptor-associated co-repressor 1 (TRAC-1) is a protein that in humans is encoded by the ''NCOR1'' gene. NCOR1 is a transcriptional coregulatory protein which contains several nuclear receptor interacting domains. In addition, NCOR1 appears to recruit histone deacetylases to DNA promoter regions. Hence NCOR1 assists nuclear receptors in the down regulation of gene expression. Loss of function of this protein significantly increases the strength and power of mouse muscles. Family It is a member of the family of nuclear receptor corepressors; the other human protein that is a member of that family is Nuclear receptor co-repressor 2.UniProNuclear receptor corepressors familyPage accessed June 26, 2016 Interactions Nuclear receptor co-repressor 1 has been shown to interact with: * Androgen receptor, * CHD1, * Calcitriol receptor * GPS2, * Glucocorticoid receptor, * HDAC3, * HDAC4, * H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Receptor Co-repressor 2
The nuclear receptor co-repressor 2 () is a transcriptional coregulatory protein that contains several nuclear receptor-interacting domains. In addition, NCOR2 appears to recruit histone deacetylases to DNA promoter regions. Hence NCOR2 assists nuclear receptors in the down regulation of target gene expression. NCOR2 is also referred to as a silencing mediator for retinoid or thyroid-hormone receptors (SMRT) or T3 receptor-associating cofactor 1 (TRAC-1). Function NCOR2/SMRT is a transcriptional coregulatory protein that contains several modulatory functional domains including multiple autonomous repression domains as well as two or three C-terminal nuclear receptor-interacting domains. NCOR2/SMRT serves as a repressive coregulatory factor (corepressor) for multiple transcription factor pathways. In this regard, NCOR2/SMRT functions as a platform protein, facilitating the recruitment of histone deacetylases to the DNA promoters bound by its interacting transcription factors. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
