Related Experiment Videos
Lipoproteins in bacteria.
1Department of Microbiology, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799.
Journal of Bioenergetics and Biomembranes
|June 1, 1990
Summary
Bacterial lipoproteins, like Braun
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Lipid modification of membrane proteins is a widespread cellular process.
- Bacterial lipoproteins, such as E. coli's Braun's lipoprotein, are synthesized as precursors.
- Lipoproteins are diverse, with shared structural and biosynthetic origins.
Purpose of the Study:
- To identify the consensus sequence for lipoprotein modification and processing.
- To elucidate the sequential enzymatic reactions involved in mature lipoprotein formation.
- To understand the common export pathway for lipoproteins.
Main Methods:
- Analysis of 26 distinct bacterial lipoprotein precursor signal sequences.
- Identification of a consensus modification/processing site.
- Review of known enzymatic pathways for lipoprotein maturation.
Main Results:
- A consensus sequence (Leu-(Ala, Ser)-(Gly, Ala)-Cys) was identified at the cleavage site of lipoprotein signal sequences.
- Lipoprotein maturation involves sequential catalysis by glyceryl transferase, O-acyl transferase(s), prolipoprotein signal peptidase (signal peptidase II), and N-acyl transferase.
- Lipoprotein export utilizes the common SecA, SecY, and SecD dependent pathway.
Conclusions:
- The identified consensus sequence is crucial for lipoprotein processing in bacteria.
- Lipoprotein biosynthesis involves a conserved series of enzymatic modifications.
- Lipoproteins are exported via a general protein translocation pathway, highlighting a commonality across diverse lipid-modified proteins.