MOBI: a web server to define and visualize structural mobility in NMR protein ensembles

Area of Science:

• Structural Biology
• Biophysics
• Computational Biology

Background:

• NMR protein ensembles contain structurally mobile regions.
• Identifying these regions is crucial for understanding protein dynamics and function.
• Existing methods for disorder identification are often specific to X-ray crystallography.

Purpose of the Study:

• To develop a web server (MOBI) for identifying structurally mobile regions in NMR protein ensembles.
• To provide a binary mobility definition analogous to intrinsic disorder in X-ray structures.
• To facilitate applications in structural analysis, comparative modeling, and disorder studies.

Main Methods:

• MOBI utilizes structural superposition and analysis of local conformational differences.
• A robust binary mobility definition is derived from these comparisons.
• The method's performance is validated against manually curated definitions from CASP8.

Main Results:

• MOBI successfully identifies structurally mobile regions in NMR protein ensembles.
• The derived binary mobility definition shows excellent agreement with established disorder definitions.
• The server outputs mobility-colored PDB files, plots, and FASTA sequences.

Conclusions:

• MOBI provides a valuable tool for analyzing protein mobility in NMR structures.
• The server's output supports diverse applications, including structural analysis and protein disorder studies.
• MOBI offers a consistent approach to mobility and disorder identification across different structural data types.