Atomic-resolution structure of cytoskeletal bactofilin by solid-state NMR

Area of Science:

• Structural biology
• Microbial biochemistry
• Biophysics

Background:

• Bactofilins are bacteria-specific cytoskeletal proteins crucial for cell processes.
• No atomic-resolution structures of bactofilins have been previously reported.
• The bactofilin BacA from Caulobacter crescentus is challenging to study using traditional methods due to insolubility and noncrystallinity.

Purpose of the Study:

• To determine the atomic structure of the bactofilin BacA.
• To provide the first atomic-resolution structural insights into the bactofilin protein family.

Main Methods:

• Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy was employed.
• NMR-derived distance restraints were used to calculate the atomic structure.
• Four-dimensional (4D) HN-HN and 2D C-C NMR spectra provided unambiguous restraints.

Main Results:

• The atomic structure of BacA was determined with 1.0 Å precision.
• The core domain of BacA forms a right-handed beta-helix with six windings.
• A triangular hydrophobic core was identified within the beta-helix structure.

Conclusions:

• The study presents the first atomic-resolution structure of a bactofilin.
• The determined structure reveals a novel right-handed beta-helical fold for BacA.
• This structural information advances the understanding of bacterial cytoskeletal proteins.