Structural determinants of polymerization reactivity of the P pilus adaptor subunit PapF.

TitleStructural determinants of polymerization reactivity of the P pilus adaptor subunit PapF.
Publication TypeJournal Article
Year of Publication2008
AuthorsVerger, D., R. J. Rose, E. Paci, G. Costakes, T. Daviter, S. Hultgren, H. Remaut, A. E. Ashcroft, S. E. Radford, and G. Waksman
Date Published2008 Nov 12
Type of Articlesmm
KeywordsAmino Acid Sequence, Bacterial Proteins, Computer Simulation, Escherichia coli Proteins, Fimbriae Proteins, Fimbriae, Bacterial, Kinetics, Models, Molecular, Molecular Chaperones, Molecular Sequence Data, Periplasmic Proteins, Protein Conformation, Proton-Translocating ATPases, Sequence Alignment

P pili are important adhesive fibers involved in kidney infection by uropathogenic Escherichia coli. Pilus subunits are characterized by a large groove resulting from lack of a beta strand. Polymerization of pilus subunits occurs via the donor-strand exchange (DSE) mechanism initiated when the N terminus of an incoming subunit interacts with the P5 region/pocket of the previously assembled subunit groove. Here, we solve the structure of the PapD:PapF complex in order to understand why PapF undergoes slow DSE. The structure reveals that the PapF P5 pocket is partially obstructed. MD simulations show this region of PapF is flexible compared with its equivalent in PapH, a subunit that also has an obstructed P5 pocket and is unable to undergo DSE. Using electrospray-ionization mass spectrometry, we show that mutations in the P5 region result in increased DSE rates. Thus, partial obstruction of the P5 pocket serves as a modulating mechanism of DSE.

Alternate JournalStructure
PubMed ID19000824
Grant List / / Biotechnology and Biological Sciences Research Council / United Kingdom
/ / Wellcome Trust / United Kingdom