Structural change in FtsZ Induced by intermolecular interactions between bound GTP and the T7 loop

Area of Science:

• Microbiology
• Structural Biology
• Biochemistry

Background:

• FtsZ is a tubulin homolog essential for bacterial cell division.
• It polymerizes into protofilaments, utilizing GTP hydrolysis, with the T7 loop playing a key role.
• Canonical FtsZ structures are known, but recent findings suggest unique conformations in Staphylococcus aureus FtsZ.

Purpose of the Study:

• To investigate the structural basis of Staphylococcus aureus FtsZ function.
• To elucidate the role of the T7 loop in FtsZ polymerization and GTPase activity through mutagenesis.

Main Methods:

• Site-directed mutagenesis of the FtsZ T7 loop.
• Analysis of FtsZ structure and GTPase activity.
• Investigating intermolecular interactions and subdomain movements.

Main Results:

• Amino acid changes in the T7 loop significantly affect FtsZ structure and GTPase activity.
• FtsZ undergoes conformational changes involving N- and C-subdomain movement.
• Interactions between bound nucleotide and T7 loop residues mediate these conformational shifts.

Conclusions:

• The T7 loop is critical for mediating conformational changes necessary for FtsZ polymerization and GTP hydrolysis.
• Staphylococcus aureus FtsZ exhibits unique structural dynamics potentially distinct from canonical FtsZ proteins.
• Understanding these mechanisms provides insights into bacterial cell division regulation.