Structural highlights
Function
PILB_THET8 ATPase component of the type IV pilus (T4P) that plays a role in surface and host cell adhesion, colonization, biofilm maturation, virulence, and twitching, a form of surface-associated motility facilitated by cycles of extension, adhesion, and retraction of T4P fibers (By similarity) (PubMed:29717025). Acts as a molecular motor to provide the energy that is required for biogenesis of the pilus and the extrusion of substrates generated in the cytoplasm (PubMed:27667690). PilB ATPase activity is also essential for T4P extension while antagonist PilT ATPase activity is required for T4P retraction (By similarity).[UniProtKB:P22608][UniProtKB:Q1D098][1] [2]
Publication Abstract from PubMed
c-di-GMP is an important second messenger in bacteria regulating, for example motility, biofilm formation, cell wall biosynthesis, infectivity, and natural transformability. It binds to a multitude of intracellular receptors. This includes proteins containing general secretory pathway II (GSPII) domains such as the N-terminal domain of the Vibrio cholerae ATPase MshE (MshEN) which binds c-di-GMP with two copies of a 24-amino acids sequence motif. The traffic ATPase PilF from Thermus thermophilus is important for type IV pilus biogenesis, twitching motility, surface attachment, and natural DNA-uptake and contains three consecutive homologous GPSII domains. We show that only two of these domains bind c-di-GMP and define the structural basis for the exceptional high affinity of the GSPII-B domain for c-di-GMP, which is 83-fold higher than that of the prototypical MshEN domain. Our work establishes an extended consensus sequence for the c-di-GMP-binding motif and highlights the role of hydrophobic residues for high-affinity recognition of c-di-GMP. Our structure is the first example for a c-di-GMP-binding domain not relying on arginine residues for ligand recognition. We also show that c-di-GMP-binding induces local unwinding of an alpha-helical turn as well as subdomain reorientation to reinforce intermolecular contacts between c-di-GMP and the C-terminal subdomain. Abolishing c-di-GMP binding to GSPII-B reduces twitching motility and surface attachment but not natural DNA-uptake. Overall, our work contributes to a better characterization of c-di-GMP binding in this class of effector domains, allows the prediction of high-affinity c-di-GMP-binding family members, and advances our understanding of the importance of c-di-GMP binding for T4P-related functions.
The structural basis for high-affinity c-di-GMP binding to the GSPII-B domain of the traffic ATPase PilF from Thermus thermophilus.,Neissner K, Keller H, Kirchner L, Dusterhus S, Duchardt-Ferner E, Averhoff B, Wohnert J J Biol Chem. 2024 Nov 29;301(1):108041. doi: 10.1016/j.jbc.2024.108041. PMID:39615687[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Mancl JM, Black WP, Robinson H, Yang Z, Schubot FD. Crystal Structure of a Type IV Pilus Assembly ATPase: Insights into the Molecular Mechanism of PilB from Thermus thermophilus. Structure. 2016 Sep 13. pii: S0969-2126(16)30243-X. doi:, 10.1016/j.str.2016.08.010. PMID:27667690 doi:http://dx.doi.org/10.1016/j.str.2016.08.010
- ↑ Sukmana A, Yang Z. The type IV pilus assembly motor PilB is a robust hexameric ATPase with complex kinetics. Biochem J. 2018 Jun 15;475(11):1979-1993. PMID:29717025 doi:10.1042/BCJ20180167
- ↑ Neißner K, Keller H, Kirchner L, Düsterhus S, Duchardt-Ferner E, Averhoff B, Wöhnert J. The structural basis for high-affinity c-di-GMP binding to the GSPII-B domain of the traffic ATPase PilF from Thermus thermophilus. J Biol Chem. 2024 Nov 29;301(1):108041. PMID:39615687 doi:10.1016/j.jbc.2024.108041
