Evidence of DNA transfer through F-pilus channels during Escherichia coli conjugation.
The mechanism of DNA transfer from Escherichia coli ( E. coli) Hfr donor strain AT2453 to recipient strain AB1157 during the conjugation process has been investigated by liquid atomic force microscopy (AFM). With the success of immobilizing both E. coli strains on gelatin-treated glass under aqueous solution, the F-pilus between an E. coli mating pair could be clearly imaged and dissected by an AFM probe. Another AFM probe functionalized with an anti-single-stranded DNA (ssDNA) antibody was then applied to detect transferring ssDNA. According to the AFM force spectrum, the transferring ssDNA could be detected only in the dissected area with a binding force of 109 +/- 5 pN measured. Our results provide direct evidence indicating that the DNA was transferred through the F-pilus channel between an E. coli mating pair during their conjugation.
Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu, Taiwan 30013.
An-Chi
AC
Shu
Chien-Chen
CC
Wu
Yi-Yang
YY
Chen
Hwei-Ling
HL
Peng
Hwan-You
HY
Chang
Tri-Rung
TR
Yew
D000906:Antibodies / Q000276:immunology; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure*; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics* / Q000648:ultrastructure*; D018625:Microscopy, Atomic Force
D000906:Antibodies; D004277:DNA, Single-Stranded