Abstract

The aim of this proposal is to continue our study by genetic means of several well-defined systems in which proteins and lipids interact. Such interactions are essential to the assembly and function of biological membranes. The systems are i) the bacterial enzyme cyclopropane fatty acid synthase, ii) morphogenesis of the lipid-containing bacteriophage PR4, and iii) malate oxidase, an enzyme which is activated by phospholipids. Cyclopropane fatty acid synthase is the only discrete enzyme known to specifically react with the nonpolar portion of a phospholipid bilayer. We propose to prepare large quantities of this enzyme by recombinant DNA techniques and to study its detailed interaction with its phospholipid substrate. Phage PR4 acquires its capsid lipid from the bacterial membrane and this process is a good model to study membrane morphogenesis by genetic means. We propose to use a combination of genetics and biochemistry to study the mechanisms whereby the phage lipids are acquired. Malate oxidase, a new project, is an enzyme that is greatly activated by phospholipids. We wish to isolate mutants of this enzyme defective in activation by lipids to determine the role of lipid binding in malate oxidase function.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM026156-10
Application #
3273644
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1983-02-01
Project End
1993-01-31
Budget Start
1989-02-01
Budget End
1990-01-31
Support Year
10
Fiscal Year
1989
Total Cost
Indirect Cost

  Institution

Name
University of Illinois Urbana-Champaign
Department
Type
Overall Medical
DUNS #
041544081
City
Champaign
State
IL
Country
United States
Zip Code
61820

  Publications

Chang, Y Y; Cronan Jr, J E (1999) Membrane cyclopropane fatty acid content is a major factor in acid resistance of Escherichia coli. Mol Microbiol 33:249-59
Eichel, J; Chang, Y Y; Riesenberg, D et al. (1999) Effect of ppGpp on Escherichia coli cyclopropane fatty acid synthesis is mediated through the RpoS sigma factor (sigmaS). J Bacteriol 181:572-6
Chang, Y Y; Cronan Jr, J E (1997) Sulfhydryl chemistry detects three conformations of the lipid binding region of Escherichia coli pyruvate oxidase. Biochemistry 36:11564-73
Grogan, D W; Cronan Jr, J E (1997) Cyclopropane ring formation in membrane lipids of bacteria. Microbiol Mol Biol Rev 61:429-41
Chang, Y Y; Cronan Jr, J E (1995) Detection by site-specific disulfide cross-linking of a conformational change in binding of Escherichia coli pyruvate oxidase to lipid bilayers. J Biol Chem 270:7896-901
Chang, Y Y; Wang, A Y; Cronan Jr, J E (1994) Expression of Escherichia coli pyruvate oxidase (PoxB) depends on the sigma factor encoded by the rpoS(katF) gene. Mol Microbiol 11:1019-28
Myung, H; Vanden Boom, T; Cronan Jr, J E (1994) The major capsid protein of the lipid-containing bacteriophage PR4 is the precursor of two other capsid proteins. Virology 198:17-24
Myung, H; Cronan Jr, J E (1994) Lipid selection in the assembly of the phospholipid bilayer membrane of the lipid-containing bacteriophage PR4. Virology 198:25-30
Wang, A Y; Cronan Jr, J E (1994) The growth phase-dependent synthesis of cyclopropane fatty acids in Escherichia coli is the result of an RpoS(KatF)-dependent promoter plus enzyme instability. Mol Microbiol 11:1009-17
Chang, Y Y; Wang, A Y; Cronan Jr, J E (1993) Molecular cloning, DNA sequencing, and biochemical analyses of Escherichia coli glyoxylate carboligase. An enzyme of the acetohydroxy acid synthase-pyruvate oxidase family. J Biol Chem 268:3911-9

Showing the most recent 10 out of 21 publications