FIGURE 21.13 The use of CRISPR-Cas technology to cause tracrRNA a gene mutation. (a) Structure of an sgRNA, which is composed of a crRNA that is connected to a tracrRNA via a linker. (b) Use of CRISPR- Cas technology. On the left side, the target gene has been repaired by NHEJ and has incurred a small deletion. This may result in gene inacti- vation. On the right side, the target gene has been repaired by HRR and now carries a point mutation. 3' Linker 5' Spacer RNA-complementary Repeat CONCEPT CHECK: How is the sgRNA different from certain components of the bacterial defense system described in Chapter 17 (see Figure 17.7)? to target gene crRNA (a) Structure of an sgRNA Region of target gene that is complementary to spacer RNA - SGRNA Cas9 Target gene The spacer region of the sgRNA binds to a complementary region of the target gene. Cas9 cleaves the target gene in both strands thereby generating a double-strand break. Cleavage Cleavage Nonhomologous end joining Homologous recombination repair Small deletion in target gene - Donor DNA Point mutation in donor DNA A double crossover swaps a portion of the target gene with the donor DNA. Point mutation now in target gene (b) Use of CRISPR-Cas technology to inactivate a gene or create a point mutation

Q: List five types of cancer in which ncRNAs can be involved.

A: Non-coding RNA (ncRNA) is an RNA molecule that is not translated into a protein. Epigenetic related…

Q: What are the protein secondary structures that differ between a normal prion and an infectious one?

A: PrPC  or prion protein is able to go through a conformational transition into an insoluble isoform…

Q: Explain how the ncRNA known as HOTAIR plays a role in gene repression.

A: RNA (Ribo Nucleic Acid) is the genetic material found in prokaryotes and eukaryotes. It is the prime…

Q: Describe the function in prokaryotic transcription of theRNA polymerase core enzyme, sigma (σ)…

A: The first step in gene expression is the transcription, which is a common phenomenon in both…

Q: Compare and contrast the roles of crRNA and tracrRNA in the defense process against bacteriophages…

A: Cas9 in conjunction with the engineered CRISPR sequences can be used to hunt down the codes and them…

Q: Explain how some lncRNAs serve as molecular decoys for RNA-binding proteins and miRNAs.

A: LncRNAs or Long noncoding RNAs are pervasive genes in important class that are involved in various o…

Q: How does miRNA act similar to RNA¡ and does the process of the mechanism differ?

A: RNAi is the biological process  in which short RNA molecules suppresses gene expression in a…

Q: How do miRNAs and siRNAs target RNAs for destruction?

A: miRNAs (microRNAs) and siRNAs (small interfering RNAs) are noncoding RNAs that play important roles…

Q: Why is having several different sigma factors a useful feature of RNA Pol in E.coli?

A: The RNA Polymerase of the bacterium Escherichia coli is composed of core enzyme of 5 subunits…

Q: What are three similarities and three differences between Chromatin Remodeling and microRNAs?

A: Chromatin remodelling is basically chemical modification of the chromatin structure for uncoiling…

Q: Imagine the four basic components of gene regulation are DNA, RNA, proteins, and small molecules.…

A: DNA and RNA are self-replicating genetical materials. Various types of RNAs are transcribed from…

Q: Explain Sigma factor recognition sequences?

A: Transcription is a process by which the information a strand of DNA is copied into a new molecule…

Q: Why is folding in the ER slow and inefficient and how are the misfolded ones degraded?

A: Endoplasmic reticulum-associated degradation (ERAD) is the QC check point of the ER which helps to…

Immunology

Immunology is the division of science involved with the immune reactions occurring in living organisms. The organisms are accustomed to evolving internal defense mechanisms to evade the invasion of microbial pathogens. Diverse cells are connected with stimulating the immune responses, which produce inhospitable conditions to the microbes prompting their lysis and thus inhibits the multiplication of the pathogens. The immune system can distinguish the pathogens through the aid of cellular intercommunication and launch responses to destroy them.