Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	A structural framework for unidirectional transport by a bacterial ABC exporter.
Journal, issue, pages	Proc Natl Acad Sci U S A, Vol. 117, Issue 32, Page 19228-19236, Year 2020
Publish date	Aug 11, 2020
Authors	Chengcheng Fan / Jens T Kaiser / Douglas C Rees /
PubMed Abstract	The ATP-binding cassette (ABC) transporter of mitochondria (Atm1) mediates iron homeostasis in eukaryotes, while the prokaryotic homolog from (Atm1) can export glutathione derivatives and confer ...The ATP-binding cassette (ABC) transporter of mitochondria (Atm1) mediates iron homeostasis in eukaryotes, while the prokaryotic homolog from (Atm1) can export glutathione derivatives and confer protection against heavy-metal toxicity. To establish the structural framework underlying the Atm1 transport mechanism, we determined eight structures by X-ray crystallography and single-particle cryo-electron microscopy in distinct conformational states, stabilized by individual disulfide crosslinks and nucleotides. As Atm1 progresses through the transport cycle, conformational changes in transmembrane helix 6 (TM6) alter the glutathione-binding site and the associated substrate-binding cavity. Significantly, kinking of TM6 in the post-ATP hydrolysis state stabilized by MgADPVO eliminates this cavity, precluding uptake of glutathione derivatives. The presence of this cavity during the transition from the inward-facing to outward-facing conformational states, and its absence in the reverse direction, thereby provide an elegant and conceptually simple mechanism for enforcing the export directionality of transport by Atm1. One of the disulfide crosslinked Atm1 variants characterized in this work retains significant glutathione transport activity, suggesting that ATP hydrolysis and substrate transport by Atm1 may involve a limited set of conformational states with minimal separation of the nucleotide-binding domains in the inward-facing conformation.
External links	Proc Natl Acad Sci U S A / PubMed:32703810 / PubMed Central
Methods	EM (single particle) / X-ray diffraction
Resolution	3.03 - 3.88 Å
Structure data	21356 6vqt EMDB-21356, PDB-6vqt: Structure of a bacterial Atm1-family ABC exporter with MgADPVO4 bound Method: EM (single particle) / Resolution: 3.03 Å 21357 6vqu EMDB-21357, PDB-6vqu: Structure of a bacterial Atm1-family ABC exporter Method: EM (single particle) / Resolution: 3.88 Å PDB-6pam: Structure of a bacterial Atm1-family ABC transporter with MgADP bound Method: X-RAY DIFFRACTION / Resolution: 3.7 Å PDB-6pan: Structure of a bacterial Atm1-family ABC exporter with ATP bound Method: X-RAY DIFFRACTION / Resolution: 3.4 Å PDB-6pao: Structure of a bacterial Atm1-family ABC exporter with ATP bound Method: X-RAY DIFFRACTION / Resolution: 3.65 Å PDB-6paq: Structure of a bacterial Atm1-family ABC exporter with ATP bound Method: X-RAY DIFFRACTION / Resolution: 3.301 Å PDB-6par: Structure of a bacterial Atm1-family ABC exporter with MgAMPPNP bound Method: X-RAY DIFFRACTION / Resolution: 3.35 Å
Chemicals	ChemComp-ADP: ADENOSINE-5'-DIPHOSPHATE / ADP, energy-carrying moleculeYM ChemComp-MG: Unknown entry ChemComp-ATP: ADENOSINE-5'-TRIPHOSPHATE / ATP, energy-carrying moleculeYM ChemComp-ANP: PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER / AMP-PNP, energy-carrying molecule analogueYM ChemComp-VO4*: VANADATE ION
Source	Novosphingobium aromaticivorans DSM 12444 (bacteria) novosphingobium aromaticivorans (strain atcc 700278 / dsm 12444 / cip 105152 / nbrc 16084 / f199) (bacteria)
Keywords	TRANSPORT PROTEIN / ABC transporter / ABC exporter / ATPase / membrane protein