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-Structure paper
Title | Structural and molecular determinants for the interaction of ExbB from Serratia marcescens and HasB, a TonB paralog. |
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Journal, issue, pages | Commun Biol, Vol. 5, Issue 1, Page 355, Year 2022 |
Publish date | Apr 13, 2022 |
Authors | Valérie Biou / Ricardo Jorge Diogo Adaixo / Mohamed Chami / Pierre-Damien Coureux / Benoist Laurent / Véronique Yvette Ntsogo Enguéné / Gisele Cardoso de Amorim / Nadia Izadi-Pruneyre / Christian Malosse / Julia Chamot-Rooke / Henning Stahlberg / Philippe Delepelaire / |
PubMed Abstract | ExbB and ExbD are cytoplasmic membrane proteins that associate with TonB to convey the energy of the proton-motive force to outer membrane receptors in Gram-negative bacteria for iron uptake. The ...ExbB and ExbD are cytoplasmic membrane proteins that associate with TonB to convey the energy of the proton-motive force to outer membrane receptors in Gram-negative bacteria for iron uptake. The opportunistic pathogen Serratia marcescens (Sm) possesses both TonB and a heme-specific TonB paralog, HasB. ExbB has a long periplasmic extension absent in other bacteria such as E. coli (Ec). Long ExbB's are found in several genera of Alphaproteobacteria, most often in correlation with a hasB gene. We investigated specificity determinants of ExbB and HasB. We determined the cryo-EM structures of ExbB and of the ExbB-ExbD complex from S. marcescens. ExbB alone is a stable pentamer, and its complex includes two ExbD monomers. We showed that ExbB extension interacts with HasB and is involved in heme acquisition and we identified key residues in the membrane domain of ExbB and ExbB, essential for function and likely involved in the interaction with TonB/HasB. Our results shed light on the class of inner membrane energy machinery formed by ExbB, ExbD and HasB. |
External links | Commun Biol / PubMed:35418619 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.2 - 4.0 Å |
Structure data | EMDB-10789, PDB-6ye4: EMDB-11806, PDB-7ajq: |
Chemicals | ChemComp-PGT: |
Source |
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Keywords | METAL TRANSPORT / membrane protein / iron uptake / proton transfer / TonB complex / MOTOR PROTEIN / TonB transport |