What would happen to regulation from a promoter undernegative control if the region where the regulatory proteinbinds was deleted? What if the promoter was under positivecontrol? Promoters from Escherichia coli under positivecontrol are not close matches to the promoter consensussequence for E. coli. Why?
Q: Lactose permease is encoded by the lacY gene of the lac operon.Suppose a mutation occurred at codon…
A: I believe this is nothing but missense mutation.
Q: The diagram below represents a hypothetical operon in the bacterium E. coli. The operon consists of…
A: Operon Operon is a place within the DNA which have several gene and all these genes are controlled…
Q: Imagine that you are studying the promoters of genes in E. coli. You notice that genes that are…
A: Lac operon in E.coli. is negatively inducible operon. It has 3 structural genes - LacZ - encodes…
Q: ne of the main lessons of this chapter is that several bacterial genes are often transcribed from a…
A: As given: Several bacterial genes are often transcribed from a single promoter into a large…
Q: . One mechanism by which antisense RNAs act as negative regulators of gene expression is by base…
A: The antisense RNA is a type of single-stranded RNA molecule that binds to the complementary…
Q: Explain why (a) inactivation of the O2 or O3 sequence of the lac operon causes only a twofold loss…
A: An operon is defined as a group of genes that have a common promoter and regulator and also…
Q: a. The original constitutive operator mutations in thelac operon were all base changes in o1. Why…
A: The original constitutive operator mutations made in the lac operon involved base changes in the O1.…
Q: Both attenuation of the trp operon in E. coli and riboswitches in B. subtilis rely on changes in the…
A: The trp operon, is a group of genes found in E. coli bacteria, encoding biosynthetic enzymes for…
Q: An electrophoretic mobility shift assay can be used to study the bindingof proteins to a segment of…
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Q: You made four mutants for a promoter sequence in DNA and studied them for transcription. The results…
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Q: m. In the figure below, the bacterial activator protein CAP and the Lac repressor have been placed…
A: Introduction :- The lac operon is a group of genes with a single promoter that encode genes for…
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Q: A bacterial operon is responsible for the production of the biosyntheticenzymes needed to make the…
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Q: Explain the features of the Initiator (Inr) elements, BREs, DPEs, and MTEs of focused promoters.
A: BASIC INFORMATION TRANSCRIPTION it is responsible for the formation of hnRNA which has the codes…
Q: Mutation in the regulatory gene in the lac operon results in the formation of an inactive repressor.…
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Q: IPTG Absent IPTG Present B-Galactosidase Permease B- Permease Galactoßsidase + O+ z+ Y+ + IS ot z+…
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Q: A bacterial species has a hypothetical sigma promoter that has the following sequence: TTGGCA -…
A: The sequence of nucleotides required for the initiation of transcription is known as the sigma…
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A: Genetics is the branch of biology that deals with the study of genes, their inheritance patterns,…
Q: The PIC is highly conserved among species, from yeast to humans. Why is the positioning of the first…
A: PIC stands for the pre-initiation complex. The core promoter region comprising of the initiator…
Q: One of the main lessons of this chapter is that severalbacterial genes are often transcribed from a…
A: Since you have asked multiple questions, we will solve the first question for you. If you want any…
Q: As discussed in the text, promoters were originally identified as consensus sequences upstream from…
A: The promoters are considered as the specific nucleotide sequence that is present in the upstream…
Q: Bacterial DNA containing an operon encoding three enzymes is introduced into chromosomal DNA in…
A: Prokaryotes are the organisms that lack the cell nucleus and membrane-bound organelles. They have…
Q: (MC) What is the function of lactose in regulation of the lac operon? 1. activates a repressor…
A: Operons are a group of enzymes and regulatory sequences.
Q: Suppose that an operon that exhibited positive control was inducible. Would the regulator gene in…
A: An operon is defined as a group of genes that have a common promoter and regulator and also…
Q: Attenuation of the trp operon was viewed as a relatively inefficient way to achieve genetic…
A: Gene is the hereditary unit occupying a specific position in the chromosome and carries information…
Q: The lac genotypes are as shown below: P+OcZ-Y+A+// P¬O+Z+Y+A+ (i) The lac operon consists of three…
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Q: What conservation laws (P- or S- invariants) can be found in the lac operon regulatory Petri net?
A: The lactose operon or lac operon is an operon that is required for the transport and metabolism of…
Q: Consider a mutant of E. coli that has an inactivating mutation in the gene for adenylate cyclase…
A: Introduction The lactose operon (also known as the lac operon) is a group of genes present in E.…
Q: Many amino acid biosynthetic operon under attenuation control are also under negative control.…
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Q: in the lac operon, both the operator (o1) and the binding site for CRP–cAMP show rotational…
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Q: In the topic about prokaryotic gene expression regulation, we learned about the LacI-, LacIS, and…
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Q: Regarding the trp operon: when levels of tryptophan are low, the ___ hairpin forms, resulting in…
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Q: Assume you have identified a new operon in bacteria (which you call the suc operon) tha encodes…
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Q: Negative supercoiling of DNA favors the transcription of genes because it facilitates unwinding.…
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Q: Many bacterial genes with related functions are arranged in operons, sets of contiguous genes that…
A: Transcription is the first od several steps of DNA based gene expression in which a particular…
Q: For some time it was not clear whether lac repressor inhibits lac operon transcription by inhibiting…
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Q: When referring to attenuation in the regulation of the trp operon it would be safe to say that, when…
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Q: In the regulation of the tryophan operon in bacteria, the co-occurence of transcription and…
A: An operon refers to a cluster a sequence of genes that are controlled by a single operator and a…
Q: To characterize the promoter of the gadA operon you made a series of deletion mutants removing…
A: Gad A gene expression is found in the bacteria. They have operon structure in which regulatory,…
Q: . In an effort to determine the location of an operator sitefor a negatively regulated gene, you…
A: An operator is a genetic sequence which allows proteins responsible for transcription to attach to…
Q: You have isolated two different mutants (reg1 andreg2) causing constitutive expression of the emu…
A: A constitutive mutation refers to the mutation in which the bacterial strains having mutation…
Q: Many promoter regions contain CAAT boxes containing consensus sequences CAAT or CCAAT approximately…
A: There are many different non-coding sequences in the DNA (deoxyribonucleic acid) that help in…
Q: . a. How many ribosomes are required (at a minimum)for the translation of trpE and trpC from a…
A: Trp operon is also called as tryptophan operon, a group of genes that encodes biosynthetic enzymes…
Q: In addition to observing similarities to the lac operon, you also notice that this gene is regulated…
A: Transcriptional attenuation negatively regulates the expression of many operons in bacteria by…
What would happen to regulation from a promoter under
negative control if the region where the regulatory protein
binds was deleted? What if the promoter was under positive
control? Promoters from Escherichia coli under positive
control are not close matches to the promoter consensus
sequence for E. coli. Why?
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- To characterize the promoter of the gadA operon you made a series of deletion mutants removing pieces of the promoter to see what would happen. The results are found below: gad promoter gada gadX gadz 450 +1 lacz activity transcription start site pH 2.0 pH 7.0 A gad promoter beta-galactosidase (lacZ) +++ 450 gad promoter beta galactosidase (lacZ) +++ +++ 300 +1 gad promoter beta galactosidase (lacZ) 150 D gad beta galactosidase (lacz) -450 150 E gad promoter beta-galactosidase (lacZ) -450 -300 Based on these results, what can you conclude about the gad promoter? O a. The promoter is only regulated by repression Ob. The promoter is regulated by a mix of activation and repression O c. The promoter is only regulated by activation O d. The promoter has multiple operators and multiple enhancersThe dlagram below represents the tryptophan operon with the trp leader MRNA transcript enlarged to represent the AUG transiation start codon, two consecutive tryptophan amino acld codons (UGGUGG), and 4 regions (1, 2, 3, and 4) that base pair to form different hairpin-loop structures in the MRNA leader region. What would happen in this MRNA leader region when cells encounter very low levels of tryptophan in Its environment? Leader region trpE trpD trpC trpB trpA DNA 5' 3' Transcription trp leader sequence mRNA UGGUGG (tryptophan codons) AUG UUUUUU 1 3 4. The translating ribosome would stall at the two tryptophan codons, causing the formation of a hairpin-loop botween regions 3 and 4 to promote transcription of the trp operon. The translating ribosome would stall at the two tryptophan codons causing formation of hairpin-loop between regions 2 and 3, which functions as an anti-lerminator of transcription The translating ribosome would stall at the two tryptophan codons causing formation…Some prion-related diseases, such as familial fatal insomnia, areinherited. How would you expect the mutation has altered the PrPgene in this case? Would it have affected the promoter, the regulatorysequences, or the coding sequence of the PrP gene?
- The diagram below represents a hypothetical operon in the bacterium E. coli. The operon consists of two structural genes (A and B), which code for the enzymes “Aase" and "Base", respectively, and also includes P (promoter) and O (operator) regions as shown. A В When a certain compound (X) is added to the growth medium of E. coli, the separate enzymes "Aase" and "Base" are both synthesized at a 50-fold higher rate than in the absence of X. (X has a molecular weight of about 200.) Which of the following statements is true of the operon described above? The region of the A gene that codes for the carboxyl-terminal amino acid of “Aase" is near the left end of the A gene. The P region contains nucleotide sequences to which the RNA polymerase holoenzyme (including the o subunit) binds specifically but which the core enzyme does not recognize. The addition of X to the growth medium causes a repressor protein to bind tightly to the O region. The mRNA copied from this operon will be covalently…INTERPRET DATA Develop a simple hypothesis that would explain the behavior of each of the following types of mutants in E. coli. Mutant a: The map position of this mutation is in the trp operon. The mutant cells are constitutive; that is, they produce all the enzymes coded for by the trp operon, even if large amounts of tryptophan are present in the growth medium. Mutant b: The map position of this mutation is in the trp operon. The mutant cells do not produce any enzymes coded for by the trp operon under any conditions. Mutant c: The map position of this mutation is some distance from the trp operon. The mutant cells are constitutive; that is, they produce all the enzymes coded for by the trp operon, even if the growth medium contains large amounts of tryptophan.Bacterial DNA containing an operon encoding three enzymes is introduced into chromosomal DNA in yeast (a eukaryote) in such a way that it is properly flanked by a promoter and a transcriptional terminator. The bacterial DNA is transcribed and the RNA correctly processed, but only the protein nearest the promoter is produced. Can you suggest why?
- The diagram below represents the tryptophan operon with the trp leader mRNA transcript enlarged to represent the AUG translation start codon, two consecutive tryptophan amino acid codons (UGGUGG), and 4 regions (1, 2, 3, and 4) that base pair to form different hairpin-loop structures in the mRNA leader region. Suppose a mutant bacteria has region 3 of the trp operon attenuator region mutated so that it cannot base pair normally. Would the bacteria grow in the absence of the amino acid tryptophan? (hint: in order for bacteria to grow in absence of tryptophan it should be able to synthesize its own tryptophan) Leader region trpE trpD trpC trpB trpA DNA 5' 3' Transcription trp leader sequence MRNA AUG UGGUGG UUUUUU 1 2 3 (tryptophan codons) There is insufficient information to answer the question. Yes No O OThe diagram below represents the tryptophan operon with the trp leader mRNA transcript enlarged to represent the AUG translation start codon, two consecutive tryptophan amino acid codons (UGGUGG), and 4 regions (1, 2, 3, and 4) that base pair to form different hairpin-loop structures in the MRNA leader region. Suppose a mutant bacteria has region 4 of the trp operon attenuator region mutated so that it cannot base pair normally. Would the bacteria grow in the absence of the amino acid tryptophan? (hint: in order for bacteria to grow in absence of tryptophan it should be able to synthesize its own tryptophan) Lead&r region trpE trpD trpC trpB trpA DNA 5' 3' Transcription trp leader sequence MRNA UGGUGG 1 (tryptophan codons) AUG UUUUUU No There is insutficient information to answer the question. O YesMutations in bacterial promoters may increase or decrease therate of gene transcription. Promoter mutations that increasetranscription are termed up-promoter mutations, and those thatdecrease transcription are termed down-promoter mutations.The sequence of the −10 site of the promoter for the lac operonis TATGTT (see Figure 14.5). Would you expect each of thefollowing mutations to be an up-promoter or down-promotermutation?A. TATGTT to TATATTB. TATGTT to TTTGTTC. TATGTT to TATGAT
- . In an effort to determine the location of an operator sitefor a negatively regulated gene, you have made a seriesof deletions within the regulatory region. The extent ofeach deletion is shown by the line underneath the sequence, and the resulting expression from the operon(i = inducible; c = constitutive; − = no expression) isalso indicated.... GGAT C T T AGCCGGCTAACATGATAAATATAA......C C T AGAATCGGCCGA TTGTA C T A TTT ATAT T ...1 i2 –3 c4 –5 ca. What can you conclude from these data about thelocation of the operator site?b. Why do you think deletions 2 and 4 show no expression of the gene?In the lac operon (below), how will expression of the genes lacZ and lacy be effect by a mutation in the repressor protein (encoded by lach) that prevents it from binding the operator sequence (lacO) in the absence of lactose? Explain the answerWhy trp operon has a higher level of expression than live operon in bacteria grown on nutrient-poor agar plates? Explain with clear reasoning