6H6N

UbiJ-SCP2 Ubiquinone synthesis protein

Summary for 6H6N

• Entry DOI: 10.2210/pdb6h6n/pdb
• Descriptor: Ubiquinone biosynthesis protein UbiJ, TERBIUM(III) ION, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: scp2 lipid binding protein ubiquinone synthesis protein, lipid binding protein
• Biological source: Escherichia coli (strain K12)
• Total number of polymer chains: 2
• Total formula weight: 29859.94

Authors

Fyfe, C.D.,Legrand, P.,Pecqueur, L.,Ciccone, L.,Lombard, M.,Fontecave, M. (deposition date: 2018-07-28, release date: 2019-02-13, Last modification date: 2024-05-15)

Primary citation

Hajj Chehade, M.,Pelosi, L.,Fyfe, C.D.,Loiseau, L.,Rascalou, B.,Brugiere, S.,Kazemzadeh, K.,Vo, C.D.,Ciccone, L.,Aussel, L.,Coute, Y.,Fontecave, M.,Barras, F.,Lombard, M.,Pierrel, F.
A Soluble Metabolon Synthesizes the Isoprenoid Lipid Ubiquinone.
Cell Chem Biol, 26:482-492.e7, 2019

PubMed Abstract: Ubiquinone (UQ) is a polyprenylated lipid that is conserved from bacteria to humans and is crucial to cellular respiration. How the cell orchestrates the efficient synthesis of UQ, which involves the modification of extremely hydrophobic substrates by multiple sequential enzymes, remains an unresolved issue. Here, we demonstrate that seven Ubi proteins form the Ubi complex, a stable metabolon that catalyzes the last six reactions of the UQ biosynthetic pathway in Escherichia coli. The SCP2 domain of UbiJ forms an extended hydrophobic cavity that binds UQ intermediates inside the 1-MDa Ubi complex. We purify the Ubi complex from cytoplasmic extracts and demonstrate that UQ biosynthesis occurs in this fraction, challenging the current thinking of a membrane-associated biosynthetic process. Collectively, our results document a rare case of stable metabolon and highlight how the supramolecular organization of soluble enzymes allows the modification of hydrophobic substrates in a hydrophilic environment.

PubMed: 30686758
DOI: 10.1016/j.chembiol.2018.12.001

Experimental method

X-RAY DIFFRACTION (2.12 Å)