Structure of the pilus assembly protein TadZ from Eubacterium rectale: implications for polar localization.

ABSTRACT: The tad (tight adherence) locus encodes a protein translocation system that produces a novel variant of type IV pili. The pilus assembly protein TadZ (called CpaE in Caulobacter crescentus) is ubiquitous in tad loci, but is absent in other type IV pilus biogenesis systems. The crystal structure of TadZ from Eubacterium rectale (ErTadZ), in complex with ATP and Mg(2+) , was determined to 2.1 Å resolution. ErTadZ contains an atypical ATPase domain with a variant of a deviant Walker-A motif that retains ATP binding capacity while displaying only low intrinsic ATPase activity. The bound ATP plays an important role in dimerization of ErTadZ. The N-terminal atypical receiver domain resembles the canonical receiver domain of response regulators, but has a degenerate, stripped-down 'active site'.

SUBMITTER: Xu Q 

PROVIDER: S-EPMC3272108 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature