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55
CHAPTER 7
Outlook
Until recently, not a lot was known about the fungal HR and PR PKSs. Even though PR-PKSs still evade the light of discovery, recent findings about HR-PKSs and the function of its domains has brought us closer to determining the internal working of the machinery of HR-PKSs domains. More and more is being written about what changes in the sequence of the domains can be performed to synthesize and modify the products of these synthases. A lot of data has been acquired regarding the structure and function of the PT and TE domains. This has helped us further in exploring the NR-PKS enzymes and brings us a step closer to the encrypted mechanism of product formation by these enzymes.
Through the research and results of experiments carried out on SAT, PT and TE domains of NR-PKSs, we have somewhat cracked the mystery of starter unit selectivity, product cyclization, and release although in PR-PKSs and HR-PKSs, the situation is unclear since they do not contain SAT and PT domains. The HR-PKSs and PR-PKSs carry out particular redox and/or methylation reactions optionally to give varieties in the structure of fungal metabolites.
Object Description
| Title | Fungal polyketides -- Review of recent findings |
| Author | Jain, Sofina M. |
| Author email | sofinaja@usc.edu; sofinajain27@gmail.com |
| Degree | Master of Science |
| Document type | Thesis |
| Degree program | Pharmacy / Pharmaceutical Sciences |
| School | School of Pharmacy |
| Date defended/completed | 2011-05-04 |
| Date submitted | 2011 |
| Restricted until | Unrestricted |
| Date published | 2011-05-05 |
| Advisor (committee chair) | Wang, Clay C. C. |
| Advisor (committee member) |
Okamoto, Curtis Toshio Shen, Wei-Chiang |
| Abstract | Fungal polyketides are a group of bioactive compounds which have found use in humans as anti-cholesterol, anti-cancer and antibiotic agents. These are synthesized by a group of enzymes called the polyketide synthases (PKSs) which are found in fungi as well as bacteria. PKSs are classified as type I, II and III. All fungal PKSs are type I iterative polyketide synthases which means they use a set of catalytic functions by a group of active domains in repetitive cycles to give the end product. Type I enzymes contain multidomains that catalyze a set of reactions.; The minimal PKS contains the domains ketosynthase (KS), acyltransferase (AT) and acyl carrier protein (ACP). The three types of PKSs are non-reduced polyketide synthases (NR-PKSs), highly-reduced polyketide synthases (HR-PKSs) and partially-reduced polyketide synthases (PR-PKSs). This classification is another form separate from type I, II and III. This paper discusses the recent research into further details of the SAT, PT and TE domain of the NR-PKSs and also recent advances in the HR-PKSs. This paper will also discuss the role of NADPH, SAM and CON domain in the HR-PKSs. We will also discuss the two off-loading mechanism of HR-PKSs that were seen in recent papers. While little research is done on PR-PKSs, NR-PKS and HR-PKS are extensively being worked on.Recent findings have brought us a step closer to the domains of the PKSs and promise us a better clearer understanding of this complex multidomain entity. |
| Keyword | fungal polyketides; HR-PKS; NR-PKS; PT domain; SAT domain; TE domain |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m3914 |
| Contributing entity | University of Southern California |
| Rights | Jain, Sofina M. |
| Repository name | Libraries, University of Southern California |
| Repository address | Los Angeles, California |
| Repository email | cisadmin@lib.usc.edu |
| Filename | etd-jain-4552 |
| Archival file | uscthesesreloadpub_Volume40/etd-jain-4552.pdf |
Description
| Title | Page 61 |
| Contributing entity | University of Southern California |
| Repository email | cisadmin@lib.usc.edu |
| Full text | 55 CHAPTER 7 Outlook Until recently, not a lot was known about the fungal HR and PR PKSs. Even though PR-PKSs still evade the light of discovery, recent findings about HR-PKSs and the function of its domains has brought us closer to determining the internal working of the machinery of HR-PKSs domains. More and more is being written about what changes in the sequence of the domains can be performed to synthesize and modify the products of these synthases. A lot of data has been acquired regarding the structure and function of the PT and TE domains. This has helped us further in exploring the NR-PKS enzymes and brings us a step closer to the encrypted mechanism of product formation by these enzymes. Through the research and results of experiments carried out on SAT, PT and TE domains of NR-PKSs, we have somewhat cracked the mystery of starter unit selectivity, product cyclization, and release although in PR-PKSs and HR-PKSs, the situation is unclear since they do not contain SAT and PT domains. The HR-PKSs and PR-PKSs carry out particular redox and/or methylation reactions optionally to give varieties in the structure of fungal metabolites. |
