1999 Fiscal Year Final Research Report Summary
Analysis of Structure-Function Relationship of the Signal Peptide-Independent Secretory Apparatus in the Gram-negative Bacterium
| Project/Area Number |
09650878
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物・生体工学
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| Research Institution | Tottori University |
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Principal Investigator |
YANASE Hideshi Tottori University Department of Biotechnology Professor, 工学部, 教授 (20158033)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMOTO Kenji Tottori University Department of Biotechnology Associate Professor, 工学部, 助手 (80283969)
KITA Keiko Tottori University Department of Biotechnology Associate Professor, 工学部, 助教授 (70234226)
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| Project Period (FY) |
1997 – 1999
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| Keywords | ABC exporter / Gram-negative bacteria / GSP / Invertase / Levansucrase / Secretion / Signal peptide-independent pathway / Zymomonas mobilis |
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| Research Abstract |
Zymomonas mobilis is a facultative anaerobic Gram-negative bacterium known as an efficient ethanol producer on glucose, and its ethanol productivity is superior to that of commercial yeast. Our focus has been on the production of fuel ethanol from agricultural wastes and municipal solid waste using Z.mobilis. To breed a Z.mobilis strain capable of converting cellulose to et hanol directory, the bacterium was transformed with the endoglucanase and β-glucosidase genes. However, the recombinant strains were still unable to produce ethanol from cellulose, presumable because the cells did secrete necessary saccharifying enzymes. We have therefore begun investigating secretory mechanism in Z.mobilis, and found that levansucrase (SucZE2) and invertase(SucZE3) are translocated via a signal peptide-independent pathway in Z.mobilis. To clarify the secretory mechanism we cloned a 1.7 kb DNA fragment containing zliE and zliS genes complements the inability of secretive production of both enzymes in a Suc- mutant from Z.mobilis ATCC29191. By subcloning each genes into two different Suc mutants of Z.mobilis, it has been found that zliE activates the production of the extracellular levansucrase and invertase, and zliS stimulates the secretion of the enzymes. The results obtained from detailed analyses of zliS function suggested that the expression of zliS affects the cell membrane to stimulate the liberation of cell-associated proteins.
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