Chromatin Structure Remodeling (RSC) Complex
Encyclopedia
Protein subunit
In structural biology, a protein subunit or subunit protein is a single protein molecule that assembles with other protein molecules to form a protein complex: a multimeric or oligomeric protein. Many naturally occurring proteins and enzymes are multimeric...
complex with the capacity to remodel the structure of chromatin
Chromatin
Chromatin is the combination of DNA and proteins that make up the contents of the nucleus of a cell. The primary functions of chromatin are; to package DNA into a smaller volume to fit in the cell, to strengthen the DNA to allow mitosis and meiosis and prevent DNA damage, and to control gene...
. It exhibits a DNA-dependent ATPase
ATPase
ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur...
activity stimulated by both free and nucleosomal DNA and a capacity to perturb nucleosome structures. It is at least 10-fold more abundant than the SWI/SNF
SWI/SNF
SWI/SNF is a yeast nucleosome remodeling complex composed of several proteins – products of the SWI and SNF genes as well as several other polypeptides...
complex and is essential for mitotic growth.
Generation of loops in dsDNA
A single molecule study using magnetic tweezersMagnetic tweezers
A magnetic tweezer is a scientific instrument for exerting and measuring forces on magnetic particles using a magnetic field gradient. Typical applications are single-molecule micromanipulation, rheology of soft matter, and studies of force-regulated processes in living cells. Forces are typically...
has observed that RSC generates DNA loops in vitro while simultaneously generating negative supercoils in the template. The figure above shows three AFM images from that study. On the left, a single RSC complex is bound to the end of a dsDNA template. The center image shows a DNA loop generated by RSC. The image on the right shows a loop generated by RSC, which contains supercoils.
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
allows the complex to translocate the DNA into a loop. RSC can release the loop either by translocating back to the original state at a comparable velocity, or by losing one of its two contacts.
RSC components
The following is list of RSC components that have been identified in yeast and the corresponding human orthologs:| yeast | human | function |
|---|---|---|
| SMARCD1 SMARCD1 SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily D member 1 is a protein that in humans is encoded by the SMARCD1 gene.-Interactions:SMARCD1 has been shown to interact with Glucocorticoid receptor.-Further reading:... , SMARCD2 SMARCD2 SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily D member 2 is a protein that in humans is encoded by the SMARCD2 gene.-Further reading:... , SMARCD3 SMARCD3 SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily D member 3 is a protein that in humans is encoded by the SMARCD3 gene.-Further reading:... |
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| SMARCC1 SMARCC1 SWI/SNF complex subunit SMARCC1 is a protein that in humans is encoded by the SMARCC1 gene.-Interactions:SMARCC1 has been shown to interact with BAZ1B, SIN3A, SMARCA2, ING1, SMARCB1 and SMARCA4.-External links:... , SMARCC2 SMARCC2 SWI/SNF complex subunit SMARCC2 is a protein that in humans is encoded by the SMARCC2 gene.-Interactions:SMARCC2 has been shown to interact with BAZ1B and SMARCA4.-External links:... |
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See also
- SWI/SNFSWI/SNFSWI/SNF is a yeast nucleosome remodeling complex composed of several proteins – products of the SWI and SNF genes as well as several other polypeptides...
(nucleosome remodeling complex) - Transcription coregulatorTranscription coregulatorIn molecular biology and genetics, transcription coregulators are proteins that interact with transcription factors to either activate or repress the transcription of specific genes. Transcription coregulators that activate gene transcription are referred to as coactivators while those that...
- Imitation SWIImitation SWIThe protein ISWI or imitation SWI of drosophila melanogaster, is the first ATPase subunit which has been isolated in the ISWI chromatin remodeling family. This protein presents high level of similarity to the SWI/SNF chromatin remodeling family in the ATPase domain...
(nucleosome remodeling complex)