2G7O

Protonation-mediated structural flexibility in the F conjugation regulatory protein, TraM

2G7O の概要

• エントリーDOI: 10.2210/pdb2g7o/pdb
• 分子名称: Protein traM (2 entities in total)
• 機能のキーワード: four helix bundle, tetramer, dna binding protein
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cytoplasm : P10026
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 7980.90

構造登録者

Lu, J.,Edwards, R.A.,Wong, J.J.,Manchak, J.,Scott, P.G.,Frost, L.S.,Glover, J.N. (登録日: 2006-02-28, 公開日: 2006-06-13, 最終更新日: 2024-02-14)

主引用文献

Lu, J.,Edwards, R.A.,Wong, J.J.,Manchak, J.,Scott, P.G.,Frost, L.S.,Glover, J.N.
Protonation-mediated structural flexibility in the F conjugation regulatory protein, TraM.
Embo J., 25:2930-2939, 2006

PubMed Abstract: TraM is essential for F plasmid-mediated bacterial conjugation, where it binds to the plasmid DNA near the origin of transfer, and recognizes a component of the transmembrane DNA transfer complex, TraD. Here we report the 1.40 A crystal structure of the TraM core tetramer (TraM58-127). TraM58-127 is a compact eight-helical bundle, in which the N-terminal helices from each protomer interact to form a central, parallel four-stranded coiled-coil, whereas each C-terminal helix packs in an antiparallel arrangement around the outside of the structure. Four protonated glutamic acid residues (Glu88) are packed in a hydrogen-bonded arrangement within the central four-helix bundle. Mutational and biophysical analyses indicate that this protonated state is in equilibrium with a deprotonated tetrameric form characterized by a lower helical content at physiological pH and temperature. Comparison of TraM to its Glu88 mutants predicted to stabilize the helical structure suggests that the protonated state is the active form for binding TraD in conjugation.

PubMed: 16710295
DOI: 10.1038/sj.emboj.7601151

実験手法

X-RAY DIFFRACTION (1.4 Å)