SmartBook Assignment 13

Which domain of a transcription factor interacts with the basal complex or with coactivators?

Activation domain

What are the two structural domains that are found in all transcriptional activator proteins?

Activation domain DNA-binding domain

Which of the following proteins are considered transcription factors?

Basal factors Activators Repressors

What proteins bind to the promoter of a gene?

Basal transcription factors

Which coactivators contain ATPase subunits and use energy from ATP hydrolysis to displace nucleosomes from a promoter?

Chromatin remodeling complexes

Stretches of DNA up to a few thousand bp in length that contain a high number of CpG dinucleotides are called _____.

CpG islands

Interactions among basal factors, Mediator, and activators bound to distant enhancers are possible because _____.

DNA is flexible and can loop

The two protein domains that are found in all activator proteins are the _____-binding domain and the _____domain.

DNA; activation

Which of the following statements best describes gene regulation in multicellular eukaryotes?

Each gene may contain several enhancer elements each with binding sites for several different transcription factors.

Which of the following are DNA-binding domains that are commonly found in transcription factors?

Helix-turn-helix Zinc finger

Which coactivators acetylate amino acid residues within histone tails?

Histone acetyl transferase enzymes

Where is the TATA box of a eukaryotic gene located?

In the promoter

How can gene regulation mechanisms be limited to only a particular gene and not its neighbors?

Insulators between genes organize chromatin and limit enhancer access to promoters.

Which of the following human disorders involve mutations of imprinted genes?

Prader-Willi syndrome Angelman syndrome

Basal factors assist the binding of _____.

RNA polymerase II to the promoter of a gene

What type of transcription factor binds to a specific DNA sequence within an enhancer and prevents the initiation of transcription of a gene?

Repressor

Eukaryotic promoters often contain a conserved sequence of approximately seven nucleotides that is located just upstream of the transcription initiation site. This sequence is called a(n) _____ box.

TATA

What protein is the key component of the basal factor complex that assembles on most promoters?

TATA box-binding protein

Which of the following statements about genomic imprinting is correct?

The allele of a gene inherited from one parent is transcriptionally active, and the allele from the other parent is transcriptionally inactive.

How do activators interact with other elements at the promoter to increase transcription levels?

They can directly interact with basal factors. They can indirectly interact with basal factors by binding to mediator.

What is the benefit of alternative splicing?

Two or more polypeptides can be derived from a single gene.

A CpG island is a DNA sequence that contains ________.

a higher than average frequency of CpG dinucleotides

Transcription factors that, when bound to an enhancer element, increase transcription of a gene above the basal level, are called transcriptional _____.

activators

The term for the mechanism that enables two or more different polypeptide sequences to be produced from a single gene is _____.

alternative splicing

The dimerization domain of an activator enables the activator to bind to _____.

another transcription factor subunit

The TATA box-binding protein (TBP) is a key component of the ______.

basal factor complex

The binding of RNA polymerase to the promoter of a gene is facilitated by _____.

basal factors

The assembly of the basal factor complex at the promoter of a gene is initiated by ____.

binding of the TATA box-binding protein to the promoter

In order to be recognized by the small ribosomal subunit, a eukaryotic mRNA is circularized through the interaction of the poly-A _____ and eIF4G.

binding protein

The field of science that combines biology, computer science, and information technology into a single discipline is called _____.

bioinformatics

The methylation of DNA at imprinting control regions (ICRs) ______.

can either activate or repress transcription

A protein that increases the rate of transcription by modifying chromatin structure but does not directly bind to the DNA itself is called a(n) _____.

coactivator

Activator proteins often increase transcription through an interaction with ______, proteins that can open local chromatin structure.

coactivators

The activation domains of transcription factors promote the activation of RNA polymerase by interacting with ______.

coactivators the basal complex

Eukaryotic repressors recruit _____ proteins to enhancers.

corepressor

When DNA in a human cell is methylated, methyl groups are added to some _______.

cytosines

Many activators are composed of two protein subunits. To form a complete activator, each protein subunit must have a(n) _____ domain.

dimerization

Activators and repressors are transcription factors that bind to DNA sequence elements called _____.

enhancer

Activators and repressors bind to ______.

enhancers

DNA-binding domains typically interact with DNA by _____.

fitting within the major groove

In order for imprinting patterns to be reset and passed on to the next generation in a sex-specific way, the methyl groups on DNA must be removed and then replaced on the DNA in ______.

germ-line cells

Prader-Willi syndrome and Angelman syndrome are examples of human developmental disorders associated with _______.

imprinting

The phenomenon in which the expression of an allele depends on which parent transmits it is known as genomic _____.

imprinting

A DNA element that organizes chromatin so that enhancers have access only to particular promoters is called a(n) _____.

insulator

Enhancer sequences can function at a distance from the promoter because the DNA between the enhancer and promoter will _____ to allow basal factors, Mediator, and activators to interact with one another.

loop

Most proteins that bind to DNA fit within the _____ groove of the double helix.

major

Genomic imprinting patterns are erased and then reestablished in a sex-specific way as germ-line cells go through _____.

meiosis

The three classes of small regulatory RNAs that have been identified are ____.

miRNA, siRNA, and piRNA

Splicing of pre-mRNA, altering mRNA stability and controlling the rate of translation are all examples of ______.

posttranscriptional gene regulation

Activators promote transcription by interacting with basal factors and RNA polymerase to recruit them to the _____ of a gene.

promoter

Activators can increase RNA synthesis by ______.

recruiting basal factors and RNA polymerase II to promoter sequences

Eukaryotic repressors inhibit transcription by _____.

recruiting corepressor proteins to enhancers

When the TATA box-binding protein binds to a gene's promoter, it ______.

recruits other proteins to the promoter

Transcription factors that bind to specific DNA sequences near genes and prevent transcription from occurring are called _____.

repressors

In ribosome profiling, the location of ribosomes along mRNAs are determined based on the fact that _____.

ribosomes protect from RNA nucleases sequences to which they are bound

Basal transcription factors bind to ______.

the promoter

Basal factors, activators, and repressors are collectively known as _____ factors.

transcription

DNA methylation at different imprinting control regions (ICRs) can either repress or activate the _____ of nearby genes.

transcription

Two DNA-binding domains that are commonly found in transcription factors are the _____ finger and the _____-turn-_____ domains.

zinc; helix; helix

The addition of a methyl (-CH3) group to the cytosine in a 5' CpG 3' dinucleotide pair is called _____.

DNA methylation

Eukaryotes have three RNA polymerases that are named RNA polymerase I, II, and III. Genes encoding proteins are transcribed by RNA polymerase _____. The major ribosomal RNAs are transcribed by RNA polymerase _____, while genes encoding the transfer RNAs (tRNAs) are transcribed by RNA polymerase _____.

II; I; III

Which of the following are required for the small ribosomal subunit to be able to recognize and bind to an mRNA?

Several initiation factors Poly-A binding protein Poly-A tail 5' cap

Select all of these that are posttranscriptional mechanisms that regulate gene expression.

Splicing of pre-mRNA Regulation of mRNA translation Controlling mRNA stability

The enhancer of a eukaryotic gene may interact with _______.

several different activators and repressors that bind to the enhancer with varying affinities

Which of the following types of RNA are small regulatory RNAs that affect the expression of other genes?

small interfering RNAs (siRNAs) Piwi-interacting RNAs (piRNAs) micro-RNAs (miRNAs)

Ribosome profiling is conceptually similar to DNA footprinting in that it identifies locations on mRNA where ribosomes are bound because ______.

those RNA sequences are protected from digestion with RNase