Identification of minor fimbrial subunits involved in biosynthesis of K88 fimbriae.
The nucleotide sequences of the genes faeF, faeH, faeI, and faeJ encoding K88 minor fimbrial subunits were determined. Analysis of the primary structure of the gene products revealed that all four proteins are synthesized with an amino-terminal signal sequence. The molecular masses of the mature FaeF, FaeH, FaeI, and FaeJ proteins were calculated to be 15,161, 25,461, 24,804, and 25,093 Da, respectively. FaeH, FaeI, and FaeJ showed significant homology with FaeG, the major fimbrial subunit of K88 fimbriae. Mutations in the respective genes were constructed. Analysis of the mutants showed that the minor fimbrial subunits FaeF and FaeH play an essential role in the biogenesis but not in the adhesive properties of the K88 fimbriae. Mutations in faeI or faeJ had no significant effect on K88 production or adhesive capacity. Specific antisera against FaeF and FaeH were raised by immunization with hybrid Cro-LacZ-FaeF and Cro-LacZ-FaeH proteins. Immunoblotting and immunoelectron microscopy revealed that FaeF and FaeH are located in or along the K88 fimbrial structure.
Bakker
D
D
Department of Molecular Microbiology, Faculty of Biology, Vrije Universiteit, Amsterdam, The Netherlands.
Willemsen
P T
PT
Willems
R H
RH
Huisman
T T
TT
Mooi
F R
FR
Oudega
B
B
Stegehuis
F
F
de Graaf
F K
FK
D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D000954:Antigens, Surface / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000648:ultrastructure; D029968:Escherichia coli Proteins; D036781:Fimbriae Proteins; D005798:Genes, Bacterial / Q000235:genetics; D016253:Microscopy, Immunoelectron; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000235:genetics; D011993:Recombinant Fusion Proteins
D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C026888:K88 antigen, E coli; D018832:Molecular Chaperones; D011993:Recombinant Fusion Proteins; C070012:faeE protein, E coli; D036781:Fimbriae Proteins; C077227:FaeH protein, E coli; C077228:FaeI protein, E coli; C077229:FaeJ protein, E coli