| NSF Org: |
MCB Division of Molecular and Cellular Biosciences |
| Recipient: |
|
| Initial Amendment Date: | September 5, 1991 |
| Latest Amendment Date: | February 3, 1994 |
| Award Number: | 9105143 |
| Award Instrument: | Continuing Grant |
| Program Manager: |
Valerie W. Hu
MCB Division of Molecular and Cellular Biosciences BIO Directorate for Biological Sciences |
| Start Date: | September 15, 1991 |
| End Date: | October 31, 1995 (Estimated) |
| Total Intended Award Amount: | $300,000.00 |
| Total Awarded Amount to Date: | $300,000.00 |
| Funds Obligated to Date: |
FY 1993 = $100,000.00 FY 1994 = $100,000.00 |
| History of Investigator: |
|
| Recipient Sponsored Research Office: |
1850 RESEARCH PARK DR STE 300 DAVIS CA US 95618-6153 (530)754-7700 |
| Sponsor Congressional District: |
|
| Primary Place of Performance: |
|
| Primary Place of
Performance Congressional District: |
|
| Unique Entity Identifier (UEI): |
|
| Parent UEI: |
|
| NSF Program(s): | MOLECULAR BIOCHEMISTRY |
| Primary Program Source: |
app-0193 app-0194 |
| Program Reference Code(s): |
|
| Program Element Code(s): |
|
| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.074 |
ABSTRACT
Most bacteria, yeasts, fungi, algae, and higher plants use inorganic sulfate as their sole sulfur source for the biosynthesis of cysteine, methionine, all reduced organic sulfur-containing coenzymes (biotin, thiamin, coenzyme A, lipoate, etc.), and a variety of structural components (plant sulfolipid, sulfated polysaccharides, etc.). The overall objective of the research is to establish the catalytic mechanism, regulatory properties, and structure-function relationships of the enzymes which catalyze the earliest steps of inorganic sulfate assimilation by fungi. Thus, a study of the enzymes (a) ATP sulfurylase, (b) APS kinase, and (c) "PAPS reductase" which catalzye, in order, (a) the formation of adenosine-5'- phosphosulfate (APS) from SO42- and ATP, (b) the formation of 3'-phosphoadenosine- 5'- phosphosulfate (PAPS) from APS and ATP, and (c) the NADPH and thioredoxin-dependent reduction of PAPS to free or bound sulfite. "PAPS reductase" is actually a multicomponent system which has never been purified to homogeneity of kinetically characterized. Most of the experiments will be performed with enzymes purified from the mesophilic fungus, Penicillium chrysogenum. Parallel studies will be performed on the enzymes from the thermophile, Penicillium duponti with the objective of identifying the structural features responsible for the remarkable heat stability of proteins from this organism. Enzyme kinetics, equilibrium binding, protein chemistry, and molecular biology methods will be used.
Please report errors in award information by writing to: awardsearch@nsf.gov.
