TY - JOUR
T1 - Hexameric and pentameric complexes of the ExbBD energizer in the ton system
AU - Maki-Yonekura, Saori
AU - Matsuoka, Rei
AU - Yamashita, Yoshiki
AU - Shimizu, Hirofumi
AU - Tanaka, Maiko
AU - Iwabuki, Fumie
AU - Yonekura, Koji
N1 - Funding Information:
We thank M Watanabe for the early stage of this work, K Hirata, K Yamashita, Y Kawano, M Yamamoto, G Ueno, and other beam line staff for their help in X-ray diffraction data acquisition at SPring-8, MB Braunfeld, AF Brilot, KA Verba, DA Agard (UCSF), A Siebert, Y Chaban, C Hecksel (Diamond), H Shigematsu, T Yokoyama (RIKEN), K Mitsuoka (Osaka University), and S De Carlo (NeCEN) for cryo-EM data collection, and S Zheng for allowing us use of MotionCor2 before the software was available to the public. We are also grateful to T Suzuki and N Dohmae for peptide mass finger printing analysis, S Oiki for use of electrophysiological devices, and D B McIntosh for help in improving the manuscript. This work was supported by the Japan Society for the Promotion of Science Grant-in-Aid for Scientific Research Grant Number 15K06986 to (SY-M), 16H04757 (to KY), 15H04675 and 17H05876 (to HS). X-ray diffraction experiments were performed at BL32XU, BL41XU and BL26 in SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) and RIKEN (Proposal Nos. 2012B1061, 2013B1085, 2014B1045, 2015A1021, 2015B2021, 2016A2530, and 2016B2530). We also acknowledge Diamond for access and support of the Cryo-EM facilities at the UK national electron bio-imaging centre (eBIC), proposal EM14838-1 and EM16817-1, funded by the Wellcome Trust, MRC and BBSRC. Japan Society for the Promotion of Science 15K06986 Saori Maki-Yonekura Japan Society for the Promotion of Science 15H04675 Hirofumi Shimizu Japan Society for the Promotion of Science 17H05876 Hirofumi Shimizu Japan Society for the Promotion of Science 16H04757 Koji Yonekura Japan Society for the Promotion of Science 20370064 Koji Yonekura The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Funding Information:
We thank M Watanabe for the early stage of this work, K Hirata, K Yamashita, Y Kawano, M Yamamoto, G Ueno, and other beam line staff for their help in X-ray diffraction data acquisition at SPring-8, MB Braunfeld, AF Brilot, KA Verba, DA Agard (UCSF), A Siebert, Y Chaban, C Hecksel (Diamond), H Shigematsu, T Yokoyama (RIKEN), K Mitsuoka (Osaka University), and S De Carlo (NeCEN) for cryo-EM data collection, and S Zheng for allowing us use of MotionCor2 before the software was available to the public. We are also grateful to T Suzuki and N Dohmae for peptide mass finger printing analysis, S Oiki for use of electrophysiological devices, and D B McIntosh for help in improving the manuscript. This work was supported by the Japan Society for the Promotion of Science Grant-in-Aid for Scientific Research Grant Number 15K06986 to (SY-M), 16H04757 (to KY), 15H04675 and 17H05876 (to HS). X-ray diffraction experiments were performed at BL32XU, BL41XU and BL26 in SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) and RIKEN (Proposal Nos. 2012B1061, 2013B1085, 2014B1045, 2015A1021, 2015B2021, 2016A2530, and 2016B2530). We also acknowledge Diamond for access and support of the Cryo-EM facilities at the UK national electron bio-imaging centre (eBIC), proposal EM14838-1 and EM16817-1, funded by the Wellcome Trust, MRC and BBSRC.
Publisher Copyright:
© Maki-Yonekura et al.
PY - 2018/4/17
Y1 - 2018/4/17
N2 - Gram-negative bacteria import essential nutrients such as iron and vitamin B 12 through outer membrane receptors. This process utilizes proton motive force harvested by the Ton system made up of three inner membrane proteins, ExbB, ExbD and TonB. ExbB and ExbD form the proton channel that energizes uptake through TonB. Recently, crystal structures suggest that the ExbB pentamer is the scaffold. Here, we present structures of hexameric complexes of ExbB and ExbD revealed by X-ray crystallography and single particle cryo-EM. Image analysis shows that hexameric and pentameric complexes coexist, with the proportion of hexamer increasing with pH. Channel current measurement and 2D crystallography support the existence and transition of the two oligomeric states in membranes. The hexameric complex consists of six ExbB subunits and three ExbD transmembrane helices enclosed within the central channel. We propose models for activation/inactivation associated with hexamer and pentamer formation and utilization of proton motive force.
AB - Gram-negative bacteria import essential nutrients such as iron and vitamin B 12 through outer membrane receptors. This process utilizes proton motive force harvested by the Ton system made up of three inner membrane proteins, ExbB, ExbD and TonB. ExbB and ExbD form the proton channel that energizes uptake through TonB. Recently, crystal structures suggest that the ExbB pentamer is the scaffold. Here, we present structures of hexameric complexes of ExbB and ExbD revealed by X-ray crystallography and single particle cryo-EM. Image analysis shows that hexameric and pentameric complexes coexist, with the proportion of hexamer increasing with pH. Channel current measurement and 2D crystallography support the existence and transition of the two oligomeric states in membranes. The hexameric complex consists of six ExbB subunits and three ExbD transmembrane helices enclosed within the central channel. We propose models for activation/inactivation associated with hexamer and pentamer formation and utilization of proton motive force.
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U2 - 10.7554/eLife.35419
DO - 10.7554/eLife.35419
M3 - Article
C2 - 29661272
AN - SCOPUS:85051859461
VL - 7
JO - eLife
JF - eLife
SN - 2050-084X
M1 - e35419
ER -