標題: Identification of Protein Domains on Major Pilin MrkA That Affects the Mechanical Properties of Klebsiella pneumoniae Type 3 Fimbriae
作者: Chan, Chia-Han
Chen, Feng-Jung
Huang, Ying-Jung
Chen, Shin-Yu
Liu, Kuo-Liang
Wang, Zhe-Chong
Peng, Hwei-Ling
Yew, Tri-Rung
Liu, Cheng-Hsien
Liou, Gunn-Guang
Hsu, Ken Y.
Chang, Hwan-You
Hsu, Long
生物科技學系
電子物理學系
光電工程學系
Department of Biological Science and Technology
Department of Electrophysics
Department of Photonics
公開日期: 15-五月-2012
摘要: The Klebsiella pneumoniae type 3 fimbriae are mainly composed of MrkA pilins that assemble into a helixlike filament. This study determined the biomechanical properties of the fimbriae and analyzed 11 site-directed MrkA mutants to identify domains that are critical for the properties. Escherichia coli strains expressing type 3 fimbriae with an Ala substitution at either F34, V45, C87, G189, T196, or Y197 resulted in a significant reduction in biofilm formation. The E. coli strain expressing MrkAG189A remained capable of producing a normal number of fimbriae. Although F34A, V45A, T196A, and Y197A substitutions expressed on E. coli strains produced sparse quantities of fimbriae, no fimbriae were observed on the cells expressing MrkAC87A. Further investigations of the mechanical properties of the MrkAG189A fimbriae with optical tweezers revealed that, unlike the wild-type fimbriae, the uncoiling force for MrkAG189A fimbriae was not constant. The MrkAG189A fimbriae also exhibited a lower enthalpy in the differential scanning calorimetry analysis. Together, these findings indicate that the mutant fimbriae are less stable than the wildtype. This study has demonstrated that the C-terminal beta strands of MrkA are required for the assembly and structural stability of fimbriae.
URI: http://hdl.handle.net/11536/16308
ISSN: 0743-7463
期刊: LANGMUIR
Volume: 28
Issue: 19
結束頁: 7428
顯示於類別:期刊論文


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  1. 000303969000014.pdf