5it5 | pdb_00005it5
Thermus thermophilus PilB core ATPase region
Structural highlights
FunctionPILB_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 PubMedType IV pili (T4P) mediate bacterial motility and virulence. The PilB/GspE family ATPases power the assembly of T4P and type 2 secretion systems. We determined the structure of the ATPase region of PilB (PilBATP) in complex with ATPgammaS to provide a model of a T4P assembly ATPase and a view of a PilB/GspE family hexamer at better than 3-A resolution. Spatial positioning and conformations of the protomers suggest a mechanism of force generation. All six PilBATP protomers contain bound ATPgammaS. Two protomers form a closed conformation poised for ATP hydrolysis. The other four molecules assume an open conformation but separate into two pairs with distinct active-site accessibilities. We propose that one pair represents the post-hydrolysis phase while the other pair appears poised for ADP/ATP exchange. Collectively, the data suggest that T4P assembly is powered by coordinating concurrent substrate binding with ATP hydrolysis across the PilB hexamer. Crystal Structure of a Type IV Pilus Assembly ATPase: Insights into the Molecular Mechanism of PilB from Thermus thermophilus.,Mancl JM, Black WP, Robinson H, Yang Z, Schubot FD Structure. 2016 Sep 13. pii: S0969-2126(16)30243-X. doi:, 10.1016/j.str.2016.08.010. PMID:27667690[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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