scholarly journals Donor-Strand Exchange in Chaperone-Assisted Pilus Assembly Proceeds through a Concerted β Strand Displacement Mechanism

2006 ◽  
Vol 22 (6) ◽  
pp. 831-842 ◽  
Author(s):  
Han Remaut ◽  
Rebecca J. Rose ◽  
Thomas J. Hannan ◽  
Scott J. Hultgren ◽  
Sheena E. Radford ◽  
...  
Keyword(s):  
Strand Exchange ◽  
Strand Displacement ◽  
Displacement Mechanism ◽  
Donor Strand Exchange ◽  
Pilus Assembly

scholarly journals Donor-Strand Exchange in Chaperone-Assisted Pilus Assembly Revealed in Atomic Detail by Molecular Dynamics

2008 ◽  
Vol 375 (4) ◽  
pp. 908-919 ◽  
Author(s):  
Rebecca J. Rose ◽  
Thomas S. Welsh ◽  
Gabriel Waksman ◽  
Alison E. Ashcroft ◽  
Sheena E. Radford ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Strand Exchange ◽  
Donor Strand Exchange ◽  
Pilus Assembly

scholarly journals Chaperone-Subunit-Usher Interactions Required for Donor Strand Exchange during Bacterial Pilus Assembly

2003 ◽  
Vol 185 (9) ◽  
pp. 2723-2730 ◽  
Author(s):  
Michelle M. Barnhart ◽  
Frederic G. Sauer ◽  
Jerome S. Pinkner ◽  
Scott J. Hultgren
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Strand Exchange ◽  
Assembly Mechanism ◽  
Type 1 Pili ◽  
Pilus Biogenesis ◽  
A Subunit ◽  
Donor Strand Exchange ◽  
Pilus Assembly

ABSTRACT The assembly of type 1 pili on the surface of uropathogenic Escherichia coli proceeds via the chaperone-usher pathway. Chaperone-subunit complexes interact with one another via a process termed donor strand complementation whereby the G1β strand of the chaperone completes the immunoglobulin (Ig) fold of the pilus subunit. Chaperone-subunit complexes are targeted to the usher, which forms a channel across the outer membrane through which pilus subunits are translocated and assembled into pili via a mechanism known as donor strand exchange. This is a mechanism whereby chaperone uncapping from a subunit is coupled with the simultaneous assembly of the subunit into the pilus fiber. Thus, in the pilus fiber, the N-terminal extension of every subunit completes the Ig fold of its neighboring subunit by occupying the same site previously occupied by the chaperone. Here, we investigated details of the donor strand exchange assembly mechanism. We discovered that the information necessary for targeting the FimC-FimH complex to the usher resides mainly in the FimH protein. This interaction is an initiating event in pilus biogenesis. We discovered that the ability of an incoming subunit (in a chaperone-subunit complex) to participate in donor strand exchange with the growing pilus depended on a previously unrecognized function of the chaperone. Furthermore, the donor strand exchange assembly mechanism between subunits was found to be necessary for subunit translocation across the outer membrane usher.

scholarly journals The archaic chaperone–usher pathways may depend on donor strand exchange for intersubunit interactions

Microbiology ◽  
2014 ◽  
Vol 160 (10) ◽  
pp. 2200-2207 ◽  
Author(s):  
Miaomiao Wu ◽  
Shihui Xu ◽  
Wei Zhu ◽  
Xiaohua Mao
Keyword(s):  
Critical Role ◽  
Strand Exchange ◽  
Single Amino Acid ◽  
Spore Coat ◽  
Coat Proteins ◽  
Subunit Interactions ◽  
System A ◽  
Spore Coat Proteins ◽  
Donor Strand Exchange ◽  
Intersubunit Interactions

Subunit–subunit interactions of the classical and alternate chaperone–usher (CU) systems have been shown to proceed through a donor strand exchange (DSE) mechanism. However, it is not known whether DSE is required for intersubunit interactions in the archaic CU system. We have previously shown that the Myxococcus xanthus Mcu system, a member of the archaic CU family that functions in spore coat formation, is likely to use the principle of donor strand complementation to medicate chaperone–subunit interactions analogous to the classical CU pathway. Here we describe the results of studies on Mcu subunit–subunit interactions. We constructed a series of N-terminal-deleted, single amino acid-mutated and donor strand-complemented Mcu subunits, and characterized their abilities to participate in subunit–subunit interactions. It appears that certain residues in both the N and C termini of McuA, a subunit of the Mcu system, play a critical role in intersubunit interactions and these interactions may involve the general principle of DSE of the classical and alternate CU systems. In addition, the specificity of the M. xanthus CU system for Mcu subunits over other spore coat proteins is demonstrated.

scholarly journals Second Order Rate Constants of Donor-Strand Exchange Reveal Individual Amino Acid Residues Important in Determining the Subunit Specificity of Pilus Biogenesis

2011 ◽  
Vol 22 (7) ◽  
pp. 1214-1223 ◽  
Author(s):  
Aneika C. Leney ◽  
Gilles Phan ◽  
William Allen ◽  
Denis Verger ◽  
Gabriel Waksman ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rate Constants ◽  
Second Order ◽  
Strand Exchange ◽  
Individual Amino Acid ◽  
Amino Acid Residues ◽  
Order Rate ◽  
Pilus Biogenesis ◽  
Donor Strand Exchange

scholarly journals Molecular Aspects of Biogenesis of Escherichia coli Dr Fimbriae: Characterization of DraB-DraE Complexes

2005 ◽  
Vol 73 (1) ◽  
pp. 135-145 ◽  
Author(s):  
Rafał Piątek ◽  
Beata Zalewska ◽  
Olga Kolaj ◽  
Michał Ferens ◽  
Bogdan Nowicki ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Disulfide Bond ◽  
Strand Exchange ◽  
Exchange Mechanism ◽  
Polymerization Process ◽  
Binary Complex ◽  
Potential Donor ◽  
Molecular Aspects ◽  
Donor Strand Exchange

ABSTRACT The Dr hemagglutinin of uropathogenic Escherichia coli is a fimbrial homopolymer of DraE subunits encoded by the dra operon. The dra operon includes the draB and draC genes, whose products exhibit homology to chaperone-usher proteins involved in the biogenesis of surface-located polymeric structures. DraB is one of the periplasmic proteins belonging to the superfamily of PapD-like chaperones. It possesses two conserved cysteine residues characteristic of the FGL subfamily of Caf1M-like chaperones. In this study we obtained evidence that DraB cysteines form a disulfide bond in a mature chaperone and have the crucial function of forming the DraB-DraE binary complex. Expression experiments showed that the DraB protein is indispensable in the folding of the DraE subunit to a form capable of polymerization. Accumulation of DraB-DraEn oligomers, composed of head-to-tail subunits and the chaperone DraB, was observed in the periplasm of a recombinant E. coli strain which expressed DraB and DraE (but not DraC). To investigate the donor strand exchange mechanism during the formation of DraE oligomers, we constructed a series of DraE N-terminal deletion mutants. Deletion of the first three N-terminal residues of a potential donor strand resulted in a DraE protein lacking an oligomerization function. In vitro data showed that the DraE disulfide bond was not needed to form a binary complex with the DraB chaperone but was essential in the polymerization process. Our data suggest that assembly of Dr fimbriae requires a chaperone-usher pathway and the donor strand exchange mechanism.

scholarly journals Adaptor Function of PapF Depends on Donor Strand Exchange in P-Pilus Biogenesis of Escherichia coli

2007 ◽  
Vol 189 (14) ◽  
pp. 5276-5283 ◽  
Author(s):  
Yvonne M. Lee ◽  
Karen W. Dodson ◽  
Scott J. Hultgren
Keyword(s):  
Escherichia Coli ◽  
Strand Exchange ◽  
Hierarchical Assembly ◽  
Pilus Biogenesis ◽  
Donor Strand Exchange

ABSTRACT P-pilus biogenesis occurs via the highly conserved chaperone-usher pathway and involves the strict coordination of multiple subunit proteins. All nonadhesin structural P-pilus subunits possess the same topology, consisting of two domains: an incomplete immunoglobulin-like fold (pilin body) and an N-terminal extension. Pilus subunits form interactions with one another through donor strand exchange, occurring at the usher, in which the N-terminal extension of an incoming subunit completes the pilin body of the preceding subunit, allowing the incorporation of the subunit into the pilus fiber. In this study, pilus subunits in which the N-terminal extension was either deleted or swapped with that of another subunit were used to examine the role of each domain of PapF in functions involving donor strand exchange and hierarchical assembly. We found that the N-terminal extension of PapF is required to adapt the PapG adhesin to the tip of the fiber. The pilin body of PapF is required to efficiently initiate assembly of the remainder of the pilus, with the assistance of the N-terminal extension. Thus, distinct functions were assigned to each region of the PapF subunit. In conclusion, all pilin subunits possess the same overall architectural topology; however, each N-terminal extension and pilin body has specific functions in pilus biogenesis.

scholarly journals Donor strand exchange and conformational changes during E. coli fimbrial formation

2010 ◽  
Vol 172 (3) ◽  
pp. 380-388 ◽  
Author(s):  
Isolde Le Trong ◽  
Pavel Aprikian ◽  
Brian A. Kidd ◽  
Wendy E. Thomas ◽  
Evgeni V. Sokurenko ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Strand Exchange ◽  
E Coli ◽  
Donor Strand Exchange
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