The solution structure of bacteriophage lambda protein W, a small morphogenetic protein possessing a novel fold

Area of Science:

• Structural biology
• Molecular biology
• Virology

Background:

• Protein W (gpW) from bacteriophage lambda plays a vital role in stabilizing phage DNA and mediating tail attachment during morphogenesis.
• Despite its small size (68 residues), gpW interacts with DNA and at least two other phage proteins, highlighting its importance in viral structure and function.

Purpose of the Study:

• To determine the solution structure of bacteriophage lambda Protein W (gpW) using NMR spectroscopy.
• To elucidate the structural basis of gpW's function in phage morphogenesis and DNA stabilization.

Main Methods:

• Nuclear Magnetic Resonance (NMR) spectroscopy was employed to determine the three-dimensional solution structure of gpW.
• Analysis of NMR data revealed the secondary and tertiary structural elements of the protein.

Main Results:

• The solution structure of gpW reveals a novel fold comprising two alpha-helices and a two-stranded beta-sheet.
• These structural elements are organized around a well-packed hydrophobic core.
• The 14 C-terminal residues, critical for gpW function, were found to be unstructured in solution.

Conclusions:

• Protein W (gpW) possesses a unique and previously undescribed protein fold.
• The unstructured nature of the C-terminal region suggests a flexible or disordered role in protein interactions or DNA binding.
• These findings provide a structural foundation for understanding gpW's essential roles in bacteriophage lambda assembly and DNA packaging.