C-terminus of FtsZ is Critical for FtsZ-FtsA Interaction

Objectives: The purpose of this study was to investigate the functional region of FtsZ-FtsA interaction in Porphyromonas gingivalis (FtsZ: filamentous temperature-sensitive protein Z) Methods: Using deletion mutagenesis, a series of C-terminal deletion PgFtsZ mutants (viz., Z¦¤C01, Z¦¤C02, Z¦¤C03) were constructed, and expressed in Escherichia coli BL21(DE3)pLysS. These mutant proteins were purified by HiTrap SP column. FtsZ-FtsA interaction was detected then with overlay assay. Results: PgFtsA bound strongly to the wild-type PgFtsZ. However, PgFtsA was shown to be significantly decrease in the affinity of the interaction with the Z¦¤C01, a mutant form of PgFtsZ in which 73 amino acid residues were removed from the C-terminus. Furthermore, Z¦¤C02 and Z¦¤C03 (missing 128 and 177 amino acid residues from the C-terminus, respectively) were a similar extent the interaction as Z¦¤C01 did, indicating that deletions of 73 residues or more from PgFtsZ C-terminus were sufficient to impair the interaction with PgFtsA. Conclusions: The C-terminus of PgFtsZ plays a critical role in the FtsZ-FtsA interaction.