The cytoskeleton of spiroplasma: a complex linear motor

Area of Science:

• Microbiology
• Cell Biology
• Bacterial Cytoskeleton

Background:

• Spiroplasma are wall-less bacteria belonging to the Mollicutes class, known for their simple cellular structure.
• They evolved through regressive evolution, representing a minimal form of self-replicating life.
• Spiroplasmas possess a unique internal cytoskeleton, discovered in 1973, which is crucial for their morphology and motility.

Purpose of the Study:

• To review the cellular and molecular structure of Spiroplasma.
• To discuss the composition and function of the Spiroplasma cytoskeleton.
• To highlight recent findings on additional cytoskeletal elements in Spiroplasma.

Main Methods:

• Structural analysis of the Spiroplasma cytoskeleton.
• Review of existing literature on Spiroplasma cellular components.
• Investigation of cytoskeletal elements like FtsZ, FtsA, EF-TU, and MreB.

Main Results:

• The Spiroplasma cytoskeleton is primarily composed of a ribbon made from the 59-kDa fib gene product.
• This ribbon follows a helical path along the cell, with repeating structural units.
• Differential fibril length changes allow for dynamic shape alterations and motility.
• Recent studies confirm the presence of FtsZ, FtsA, EF-TU, and MreB in Spiroplasma.

Conclusions:

• The Spiroplasma cytoskeleton is a complex structure essential for their unique helical shape and motility.
• The fib gene product forms the core ribbon, enabling dynamic shape changes.
• The presence of additional cytoskeletal proteins broadens our understanding of Spiroplasma cell biology.