Identification of the Coiled-coil Domains of Enterococcus faecalis DivIVA that Mediate Oligomerization and their Importance for Biological Function

• Published in: Journal of biochemistry (Tokyo) 2008-07, Vol.144 (1), p.63-76
• Main Authors: Rigden, Marc D, Baier, Cherise, Ramirez-Arcos, Sandra, Liao, Mingmin, Wang, Monica, Dillon, Jo-Anne R
• Format: Article
• Language: English
• Subjects: Bacillus subtilis; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Cell Cycle Proteins - chemistry; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cell Division; DivIVA; Enterococcus faecalis; Enterococcus faecalis - cytology; Enterococcus faecalis - genetics; Escherichia coli; Escherichia coli - cytology; Escherichia coli - genetics; Molecular Weight; mutagenesis; Mutation; protein interactions; Protein Structure, Tertiary
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/jb/mvn044

Bacillus subtilis (Bs) DivIVA comprises coiled-coil structures and self-associates forming a 10-12 mer complex in vitro. Using bioinformatic approaches, we determined that Enterococcus faecalis (Ef) DivIVA comprises four coiled-coil domains, one at the N-terminus, the second and the third in the central region of the protein and the fourth at the C-terminus. We determined that DivIVAEf self-interacts and forms a 10-12 multimeric complex. Point mutations or deletions of the central regions predicted bioinformatically to disrupt the coiled-coil structures either eliminated or weakened DivIVAEf self-interaction and reduced oligomerization. Mutations disrupting the N- and C-terminal coiled-coils of DivIVAEf did not affect DivIVAEf oligomerization. The introduction of DivIVAEf mutations to both the N-terminal and the central coiled-coil domains were lethal unless rescued by expressing wild-type DivIVAEf in trans. E. faecalis cells expressing these mutations displayed aberrant cell morphology, indicating disruption of the normal cell division phenotype. The results in E. faecalis also indicate that both the N-terminal and the central coiled-coil structures of DivIVAEf are indispensable for proper biological function. Overexpression of wild-type DivIVAEf in both rod-shaped and round Escherichia coli cells resulted in morphological changes, while the overexpression of DivIVAEf mutations failed to induce such alterations.