Aquifex aeolicus PilT, Homologue of a Surface Motility Protein, Is a Thermostable Oligomeric NTPase

AUTOR(ES)

Herdendorf, Timothy J.

FONTE

American Society for Microbiology

RESUMO

Bacterial surface motility works by retraction of surface-attached type IV pili. This retraction requires the PilT protein, a member of a large family of putative NTPases from type II and IV secretion systems. In this study, the PilT homologue from the thermophilic eubacterium Aquifex aeolicus was cloned, overexpressed, and purified. A. aeolicus PilT was shown to be a thermostable ATPase with a specific activity of 15.7 nmol of ATP hydrolyzed/min/mg of protein. This activity was abolished when a conserved lysine in the nucleotide-binding motif was altered. The substrate specificity was low; UTP, CTP, ATP, GTP, dATP, and dGTP served as substrates, UTP having the highest activity of these in vitro. Based on sedimentation equilibrium and size exclusion chromatography, PilT was identified as a ≈5- to 6-subunit oligomer. Potential implications of the NTPase activity of PilT in pilus retraction are discussed.

Documentos Relacionados

• The Legionella pneumophila PilT Homologue DotB Exhibits ATPase Activity That Is Critical for Intracellular Growth
• Suppression of an absolute defect in Type IV pilus biogenesis by loss-of-function mutations in pilT, a twitching motility gene in Neisseria gonorrhoeae
• Thermophile-specific proteins: the gene product of aq_1292 from Aquifex aeolicus is an NTPase
• Requirement of Novel Competence Genes pilT and pilU of Pseudomonas stutzeri for Natural Transformation and Suppression of pilT Deficiency by a Hexahistidine Tag on the Type IV Pilus Protein PilAI
• Identification, localization, and distribution of the PilT protein in Neisseria gonorrhoeae.