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Structural basis of chaperone self-capping in P pilus biogenesis.

ABSTRACT: PapD is an immunoglobulin-like chaperone that mediates the assembly of P pili in uropathogenic strains of Escherichia coli. It binds and caps interactive surfaces on pilus subunits to prevent their premature associations in the periplasm. We elucidated the structural basis of a mechanism whereby PapD also interacts with itself, capping its own subunit binding surface. Crystal structures of dimeric forms of PapD revealed that this self-capping mechanism involves a rearrangement and ordering of the C2-D2 and F1-G1 loops upon dimerization which might ensure that a stable dimer is not formed in solution in spite of a relatively large dimer interface. An analysis of site directed mutations revealed that chaperone dimerization requires the same surface that is otherwise used to bind subunits.

SUBMITTER: Hung DL

PROVIDER: S-EPMC22208 | biostudies-literature | 1999 Jul

REPOSITORIES: biostudies-literature

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Structural basis of chaperone self-capping in P pilus biogenesis.

Hung D L DL Pinkner J S JS Knight S D SD Hultgren S J SJ

Proceedings of the National Academy of Sciences of the United States of America 19990701 14

PapD is an immunoglobulin-like chaperone that mediates the assembly of P pili in uropathogenic strains of Escherichia coli. It binds and caps interactive surfaces on pilus subunits to prevent their premature associations in the periplasm. We elucidated the structural basis of a mechanism whereby PapD also interacts with itself, capping its own subunit binding surface. Crystal structures of dimeric forms of PapD revealed that this self-capping mechanism involves a rearrangement and ordering of th ...[more]

PMID: 10393968

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