title: MrkF is a component of type 3 fimbriae in Klebsiella pneumoniae.
abstract: Klebsiella pneumoniae type 3 fimbriae are encoded by mrkABCDF genes which produce the major pilin subunit MrkA, chaperone MrkB, outer membrane usher MrkC, adhesin MrkD and MrkF of unknown function, respectively. RT-PCR analysis demonstrated that the mrkF gene is contained within the mrk operon. Deletion of mrkF in K. pneumoniae CG43 was found to reduce biofilm formation. A higher level of biofilm formation activity was also observed in recombinant Escherichia coli JM109[pmrkABCDF] compared to that observed for JM109[pmrkABCD]. Immunoelectron microscopy analysis of recombinant type 3 fimbriae using anti-MrkA and anti-MrkF antibody-labeled gold particles revealed that MrkF intermittently inserted into the MrkA filament. An interaction between recombinant MrkA and MrkF was demonstrated by co-immunoprecipitation analysis, further supporting the notion that MrkF is a structural component of the fimbriae. Intriguingly, the incorporation of MrkF appeared to decrease fimbrial length but increased activity of autoaggregation and biofilm formation in the bacteria JM109[pmrkABCDF]. This suggested that MrkF may play a role in assembly of the filament.
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, Hsin Chu, 30050 Taiwan, Republic of China.
authors.forename: Ying-Jung
authors.initials: YJ
authors.lastname: Huang
authors.forename: Hsin-Wei
authors.initials: HW
authors.lastname: Liao
authors.forename: Chien-Chen
authors.initials: CC
authors.lastname: Wu
authors.forename: Hwei-Ling
authors.initials: HL
authors.lastname: Peng
mesh_terms: D000818:Animals; D018441:Biofilms; D004926:Escherichia coli / Q000235:genetics; D005260:Female; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D007711:Klebsiella pneumoniae / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D005810:Multigene Family; D009876:Operon; D012329:RNA, Bacterial / Q000235:genetics; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D012329:RNA, Bacterial; D011994:Recombinant Proteins; D036781:Fimbriae Proteins