Isolation of the Rhizobium leguminosarum NodF nodulation protein: NodF carries a 4'-phosphopantetheine prosthetic group.

摘要: Abstract Rhizobium species produce a protein product of the nodF gene that has limited but recognizable homology to well-characterized acyl carrier (ACP) Escherichia coli. NodF functions together with NodE in generating host-specific response plant host interchange signals leading effective nodulation roots (H.P. Spaink, J. Weinman, M.A. Djordjevic, C.A. Wijffelman, R.J.H. Okker, and B. J.J. Lugtenberg, EMBO 8:2811-2818, 1989; Scheres, C. van de Wiel, A. Zalensky, Horvath, H. Eck, F. Zwartkruis, A.M. Wolters, T. Gloudemans, Kammen, Bisseling, Cell 60:281-294, 1990). The nodFE region Rhizobium leguminosarum been cloned into multicopy plasmid shown R. code for flavonoid-inducible is effectively labeled by radioactive beta-alanine added growth medium. After purification, migrates as single band an apparent molecular weight 5,000 during sodium dodecyl sulfate-polyacrylamide gel electrophoresis, more rapidly than E. coli ACP. In contrast, native gels resolved two bands, both identified analysis amino terminus migrating slowly Pulse-chase experiments suggested slower-moving may be precursor faster band. carries 4'-phosphopantetheine prosthetic group. A fusion under control lac promoter expressed beta-alanine, indicating it recognized ACP synthase phosphodiesterase coli, which catalyzes release phosphopantetheine from ACP, does not remove NodF.