| Literature References | 1. HUNG, D.L., KNIGHT, S.D., WOODS, R.M., PINKNER, J.S., AND HULTGREN, S.J.
Molecular basis of two subfamilies of immunoglobulin-like chaperones.
EMBO J. 15(15) 3792-3805 (1996).
2. HULTGREN, S.J., NORMARK, S. AND ABRAHAM, S.N.
Chaperone-assisted assembly and molecular architecture of adhesive pili.
ANNU.REV.MICROBIOL. 45 383-415 (1991).
3. HOLMGREN, A., KUEHN, M.J., BRANDEN, C.I., AND HULTGREN, S.J.
Conserved immunoglobulin-like features in a family of periplasmic pilus
chaperones in bacteria.
EMBO J. 11(4) 1617-1622 (1992).
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| Documentation | Pili are supramolecular structures present on the surface of most Gram-
negative bacteria that are involved in the recognition of host receptors.
Many interactive subunits are required to assemble pili, but their assembly
only takes place after translocation across the cytoplasmic membrane.
Periplasmic chaperones assist pili assembly by binding to the subunits,
thereby preventing premature aggregation [1,2]. This family of chaperones
are structurally, and possibly evolutionarily, related to the immunoglobulin
superfamily [3]: they contain two globular domains, with a topology
identical to an immunoglobulin fold.
CHAPERONPILI is a 5-element fingerprint that provides a signature for the
pili chaperone protein family. The fingerprint was derived from an initial
alignment of 13 sequences: the motifs were drawn from conserved regions
spanning the full alignment length - motif 3 includes the region encoded by
PROSITE pattern PILI_CHAPERONE (PS00635), a highly-conserved section located
in the C-terminus of the first globular domain. Four iterations on OWL30.2
were required to reach convergence, at which point a true set comprising 47
sequences was identified. Two partial matches were also found, ECU505471
and YHCA_ECOLI, both of which are related proteins that fail to match two
or more motifs.
An update on SPTR37_9f identified a true set of 45 sequences, and 1
partial match.
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