5XLK

Crystal structure of the flagellar cap protein FliD D2-D3 domains from Serratia marcescens in Space group I422

Summary for 5XLK

• Entry DOI: 10.2210/pdb5xlk/pdb
• Descriptor: Flagellar hook-associated protein 2, ZINC ION (2 entities in total)
• Functional Keywords: bacterial flagellar cap protein, structural protein
• Biological source: Serratia marcescens
• Cellular location: Secreted : A0A0P0QFX8
• Total number of polymer chains: 3
• Total formula weight: 66048.92

Authors

Cho, S.Y.,Song, W.S.,Hong, H.J.,Yoon, S.I. (deposition date: 2017-05-10, release date: 2017-06-14, Last modification date: 2023-11-22)

Primary citation

Cho, S.Y.,Song, W.S.,Hong, H.J.,Lee, G.S.,Kang, S.G.,Ko, H.J.,Kim, P.H.,Yoon, S.I.
Tetrameric structure of the flagellar cap protein FliD from Serratia marcescens.
Biochem. Biophys. Res. Commun., 489:63-69, 2017

PubMed Abstract: Bacterial motility is provided by the flagellum. FliD is located at the distal end of the flagellum and plays a key role in the insertion of each flagellin protein at the growing tip of the flagellar filament. Because FliD functions as an oligomer, the determination of the oligomeric state of FliD is critical to understanding the molecular mechanism of FliD-mediated flagellar growth. FliD has been shown to adopt a pentameric or a hexameric structure depending on the bacterial species. Here, we report another distinct oligomeric form of FliD based on structural and biochemical studies. The crystal structures of the D2 and D3 domains of Serratia marcescens FliD (smFliD) were determined in two crystal forms and together revealed that smFliD assembles into a tetrameric architecture that resembles a four-pointed star plate. smFliD tetramerization was also confirmed in solution by cross-linking experiments. Although smFliD oligomerizes in a head-to-tail orientation using a common primary binding interface between the D2 and D3' domains (the prime denotes the second subunit in the oligomer) similarly to other FliD orthologs, the smFliD tetramer diverges to present a unique secondary D2-D2' binding interface. Our structure-based comparative analysis of FliD suggests that bacteria have developed diverse species-specific oligomeric forms of FliD that range from tetramers to hexamers for flagellar growth.

PubMed: 28527888
DOI: 10.1016/j.bbrc.2017.05.093

Experimental method

X-RAY DIFFRACTION (3.05 Å)