Zinc Finger Nucleases Essay Example | Topics and Well Written Essays - 3000 words

Zinc Finger Nucleases - Essay Example When mRNA or genes coding for modified ZFNs are expressed in cells they introduce site-specific breaks in target DNA, which when repaired by the cellular DNA repair machinery, result in substitutions or deletions at the cleavage site, thus introducing a site-specific mutation. 1) Cite four research papers that use this method (20%) and describe, with the aid of diagrams if necessary. 2) How ZFNs can be used to carry out site-directed mutagenesis and how the use of genome sequence data is essential to use this technique (80%). Upper Word Limit: †¦3000 RELEVANT MODULE LEARNING OBJECTIVES 1. Describe the different means of making targeted sets of mutations to systematically analyse gene function. 2. Be able to develop practical expertise in applying bioinformatics methods to biological problems 3. Have further developed your skills in information retrieval from library and Web site sources. 4. Have gained additional experience in critical reading of original literature. 5. Have dev eloped further your ability to study To be signed by the student I have read and understood the University regulations and the Departmental guidelines on cheating in my Degree Handbook. I confirm that, in preparing this piece of work, I have followed those guidelines. I understand that my work may be submitted for checking to the JISC Plagiarism Detection Service and that use of this Service complies with UK Data Protection Law. Word Count: †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦2730 words excluding cover page and references†¦ Signature of student†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦..†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. Date†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. Failure to sign and clearly identify this piece of work will result in no marks being awarded. Note: The standard turnaround time for marked coursework is four weeks. Turnaround times for coursework involving multiple and/or ext ernal markers may be longer. In these cases the module supervisor will advise when the coursework will be returned. Site-Directed Mutagenesis by Engineered Zinc Finger Nucleases Background A zinc finger refers to a secondary structural motif of certain proteins. The zinc finger folds in a manner that allows it to coordinate or hold a zinc metal. There are several zinc finger motifs; the most common is the Cys2His2 zinc finger that consists of an antiparallel ?-sheet and an ?-helix coordinated by 2 His and 2 Cys residues that bind a zinc atom. The zinc finger proteins are involved in many reactions like mediating protein-protein interactions, RNA binding, but they are most known to be involved DNA sequence-specific binding. Two or more zinc fingers comprise the DNA-binding domain. Each zinc finger domain binds to three bases on the DNA. If there are more zinc fingers, then more bases are bound. Bound regions by the zinc fingers are usually three bp apart, and bind to the major groove of DNA. The capacity of the zinc finger proteins to recognize highly specific DNA sequences for binding was exploited by researchers to produce, design, or engineer zinc finger nucleases (ZFN) that can cut the target DNA at specific sites. Usually, these zinc finger nucleases have similar motifs as that of Cys2His2 zinc finger protein. In order to cut a specific target site on the DNA, the engineered zinc finger protein was fused with the cleavage site of FokI endonuclease, which is a restriction enzyme. FokI has a strict requirement for dimerization to the DNA; this is the reason why two different ZFNs are designed in opposing direction to bind the FokI restriction site (Figure 1). One ZNF can have several zinc fingers but only one nuclease domain. Many engineered ZFNs are targeted to attach to different DNA regions. After the ZFNs specifically bind the target DNA regions, the Fok1