Protein
Outer membrane usher protein PapC
Function
Involved in the export and assembly of pili subunits across the outer membrane. Forms a hexameric ring-shaped pore in the outer bacterial membrane. The 2 nanometer-diameter pore allows the passage of the thin tip fibrillum. As for the rod, it probably unwinds into linear fibers which would therefore be narrow enough to pass through the pore.
Similarity
Belongs to the fimbrial export usher family.
Sequence
MKDRIPFAVNNITCVILLSLFCNAASAVEFNTDVLDAADKKNIDFTRFSEAGYVLPGQYLLDVIVNGQSISPASLQISFVEPALSGDKAEKKLPQACLTSDMVRLMGLTAESLDKVVYWHDGQCADFHGLPGVDIRPDTGAGVLRINMPQAWLEYSDATWLPPSRWDDGIPGLMLDYNLNGTVSRNYQGGDSHQFSYNGTVGGNLGPWRLRADYQGSQEQSRYNGEKTTNRNFTWSRFYLFRAIPRWRANLTLGENNINSDIFRSWSYTGASLESDDRMLPPRLRGYAPQITGIAETNARVVVSQQGRVLYDSMVPAGPFSIQDLDSSVRGRLDVEVIEQNGRKKTFQVDTASVPYLTRPGQVRYKLVSGRSRGYGHETEGPVFATGEASWGLSNQWSLYGGAVLAGDYNALAAGAGWDLGVPGTLSADITQSVARIEGERTFQGKSWRLSYSKRFDNADADITFAGYRFSERNYMTMEQYLNARYRNDYSSREKEMYTVTLNKNVADWNTSFNLQYSRQTYWDIRKTDYYTVSVNRYFNVFGLQGVAVGLSASRSKYLGRDNDSAYLRISVPLGTGTASYSGSMSNDRYVNMAGYTDTFNDGLDSYSLNAGLNSGGGLTSQRQINAYYSHRSPLANLSANIASLQKGYTSFGVSASGGATITGKGAALHAGGMSGGTRLLVDTDGVGGVPVDGGQVVTNRWGTGVVTDISSYYRNTTSVDLKRLPDDVEATRSVVESALTEGAIGYRKFSVLKGKRLFAILRLADGSQPPFGASVTSEKGRELGMVADEGLAWLSGVTPGETLSVNWDGKIQCQVNVPETAISDQQLLLPCTPQK