What is the role of ATP-dependent chromatin-remodeling?

ATP-dependent chromatin remodelers have established roles in regulating gene expression. Chromatin remodeling complexes (CRCs) are made up of multiple specialized proteins that play essential roles in packaging and regulating access to the genome throughout the cell cycle.

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How do chromatin remodeling complexes work quizlet?

How do chromatin-remodeling complexes work? They use the energy from ATP hydrolysis to alter the arrangement of nucleosomes, rendering certain regions of the DNA more acceible to other proteins. The tails of the core histone proteins can be chemically modified by the covalent addition of what type of chemical group?

What do chromatin remodeling complexes use for energy?

Chromatin remodelers are part of superfamily 2 (SF2) helicases that contain DEAD-box ATPase subunits [11]. These complexes utilize the energy of ATP to alter the contacts between histones and DNA to reposition or edit nucleosome composition [12].

How do chromatin remodeling complexes recognize the genes?

The many different remodeling enzymes recognize different histone modifications, DNA structures/sequences and RNA signals that target them to specific genomic loci. To recognize these chromatin signals remodeling complexes have dedicated protein domains, termed reader domains.

How is chromatin remodeled quizlet?

Chromatin Remodeling Complex: slide the nucleosome to a different location or eject it from the DNA or replace it with a new nucleosome that contains a variant histone subunit.

What is the function of ATP dependent chromatin remodeling complexes quizlet?

ATP-dependent chromatin remodeling may effect position of nucleosomes, evict histones, and may replace histones with histone variants. The addition of methyl groups to bases of DNA after DNA synthesis. Inhibits initiation of transcription when occurs near promoter.

Does chromatin-remodeling complex use ATP?

SANT domain is found in several ATP-dependent chromatin remodeling complexes such as RSC and ISWI, and in histone modifying enzymes Ada2, NCoR that interacts with HDAC and Sin3, and SPR1 from C.

Why is ATP needed for chromatin-remodeling?

ATP-dependent chromatin remodeling complexes use the energy of ATP hydrolysis to alter chromatin architecture by repositioning, assembling, mobilizing, and restructuring nucleosomes.

What role do chromatin remodelers play in eukaryotic gene expression?

What role do chromatin remodelers play in eukaryotic gene expression? Chromatin remodeler enzymes can enzymatically change the distribution or composition of nucleosomes (histone octamers). a eukaryotic cis-acting DNA regulatory sequence to which transacting factors bind and stimulate transcription.

What does the chromatin-remodeling complex expose on the DNA that affects transcription?

There is also evidence that chromatin-remodeling complexes work together with enzymes that alter histones, such as acetyltransferase enzymes (see next section), to change chromatin structure and expose DNA for transcription.

What are chromatin-remodeling factors?

Chromatin remodeling factors are key components involved in this process and include histone chaperones, histone modifying enzymes and ATP-dependent chromatin remodeling complexes. Several of these factors interact directly with components of the replication machinery.

What part of the chromatin fiber does the remodeling complex attach to quizlet?

book: (A) Using the energy of ATP hydrolysis, the remodeling complex is thought to push on the DNA of its bound nucleosome and loosen its attachment to the nucleosome core.

What is the name of the protein that binds the two separated DNA strands to keep them from base pairing again before they can be replicated?

FEEDBACK: As a replication fork travels along the chromosome, the helicase pries apart the two strands of the double-helix. Single-strand binding protein holds these two strands apart and keeps them from reforming base pairs by binding to the single-stranded DNA.

How does methylation of histone tails affect the accessibility of DNA quizlet?

Methylation of histone tails in chromatin can promote condensation of the chromatin. Acetylation of histone tails in chromatin allows access to DNA for transcription. One of the mechanisms by which eukaryotes regulate gene expression is through modifications to chromatin structure.

How does methylation of histone tails affect the accessibility of DNA?

Methylation and demethylation of histones turns the genes in DNA “off” and “on,” respectively, either by loosening their tails, thereby allowing transcription factors and other proteins to access the DNA, or by encompassing their tails around the DNA, thereby restricting access to the DNA.

What is the function of ATP dependent chromatin remodeling complexes multiple choice question?

One aspect of ATP-dependent chromatin-remodeling complexes that has not been studied extensively is their function in the different phases of the cell cycle. These complexes have been implicated in the regulation of cellular growth and proliferation.

What does histone modification do?

Histone modifications regulate the physical properties of chromatin, and its corresponding transcriptional state, either directly (eg acetyl groups that repel negatively charged DNA to create open chromatin conformation) or via protein adaptors termed effectors.

How does SWI SNF work?

The SWI/SNF subfamily provides crucial nucleosome rearrangement, which is seen as ejection and/or sliding. The movement of nucleosomes provides easier access to the chromatin, allowing genes to be activated or repressed.

How do changes in histone modifications lead to changes in chromatin structure?

Answer and Explanation: Histone modifications lead to the change in chromatin structure, because it’s alters the affinity between the histone optima and the dna. Histone modification has no effect on the position of histones which are set during DNA replication.

What are nucleosome remodeling complexes?

Nucleosome remodeling complexes are involved in both the activation and repression of gene expression. Mutation of their subunits in yeast often leads to as many genes showing an increase in expression as those whose expression decreases (Hargreaves and Crabtree 2011).

Is histone a chaperone?

Histone chaperones are now broadly defined as a group of proteins that bind histones and regulate nucleosome assembly1. In general, histone chaperones can be classified either as H3–H4 or H2A–H2B chaperones based on their preferential binding to H3–H4 or H2A–H2B, respectively.

What is the relationship between degree of methylation of DNA and degree of gene expression?

The relationship between methylation and gene expression is complex, with high levels of gene expression often associated with low promoter methylation [5] but elevated gene body methylation [6], and the causality relationships have not yet been determined.

Why are interactions between RNA polymerase II and GTFs important for transcription in eukaryotes?

Interactions between RNA polymerase and GTFs increase the rate of transcription because GTFs act as enhancers. RNA polymerase II and GTFs must interact for the polymerase to bind properly at the core promoter site of the DNA.

How does chromatin remodeling increase transcriptional initiation?

As chromatin is condensed into the primary nucleosome structure, DNA becomes less accessible for transcription factors. With the loosening of this chromatin structure, however, transcription machinery is better able to access the genomic DNA, and transcription is thus promoted.

Where does chromatin remodeling occur?

In eukaryotes, DNA is tightly wound into a complex called chromatin. Thanks to the process of chromatin remodeling, this complex can be “opened” so that specific genes are expressed.

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