The major protein from lipid bodies of maize. Characterization and structure based on cDNA cloning

Area of Science:

• Plant Biology
• Molecular Biology
• Biochemistry

Background:

• Plant seeds store energy as triacylglycerols within lipid bodies.
• Lipid bodies are composed of a lipid core, a phospholipid monolayer, and embedded proteins.

Purpose of the Study:

• To clone and sequence the complementary DNA (cDNA) for the major protein (L3) associated with maize lipid bodies.
• To analyze the structure and function of the L3 protein.

Main Methods:

• Cloning and sequencing of a nearly full-length L3-cDNA from maize.
• Hybrid-selected translation analysis to identify the L3-cDNA clone.
• Bioinformatic analyses of the deduced amino acid sequence for secondary structure and hydropathy.

Main Results:

• A nearly full-length L3-cDNA clone was obtained, encoding a polypeptide matching authentic L3 protein characteristics.
• The deduced L3 protein sequence suggests three structural domains: a hydrophobic core flanked by hydrophilic and amphipathic alpha-helices.
• The L3 protein's structure indicates suitability for interacting with both lipid and phospholipid components of lipid bodies.

Conclusions:

• The L3 protein possesses a unique structure adapted for its role in maize lipid bodies.
• A model for L3 protein topology on the lipid body surface is proposed.
• The study provides insights into the unusual structure of lipid body proteins compared to other lipid-associated proteins.