6ZN7

MaeB malic enzyme domain apoprotein

Summary for 6ZN7

• Entry DOI: 10.2210/pdb6zn7/pdb
• Related: 6ZN4
• Descriptor: NADP-dependent malate dehydrogenase,Malate dehydrogenase, MAGNESIUM ION, NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, ... (4 entities in total)
• Functional Keywords: malic enzyme, oxidoreductase
• Biological source: Bdellovibrio bacteriovorus (strain ATCC 15356 / DSM 50701 / NCIB 9529 / HD100); More
• Total number of polymer chains: 2
• Total formula weight: 97747.14

Authors

Lovering, A.L.,Harding, C.J. (deposition date: 2020-07-06, release date: 2021-02-17, Last modification date: 2024-01-31)

Primary citation

Harding, C.J.,Cadby, I.T.,Moynihan, P.J.,Lovering, A.L.
A rotary mechanism for allostery in bacterial hybrid malic enzymes.
Nat Commun, 12:1228-1228, 2021

PubMed Abstract: Bacterial hybrid malic enzymes (MaeB grouping, multidomain) catalyse the transformation of malate to pyruvate, and are a major contributor to cellular reducing power and carbon flux. Distinct from other malic enzyme subtypes, the hybrid enzymes are regulated by acetyl-CoA, a molecular indicator of the metabolic state of the cell. Here we solve the structure of a MaeB protein, which reveals hybrid enzymes use the appended phosphotransacetylase (PTA) domain to form a hexameric sensor that communicates acetyl-CoA occupancy to the malic enzyme active site, 60 Å away. We demonstrate that allostery is governed by a large-scale rearrangement that rotates the catalytic subunits 70° between the two states, identifying MaeB as a new model enzyme for the study of ligand-induced conformational change. Our work provides the mechanistic basis for metabolic control of hybrid malic enzymes, and identifies inhibition-insensitive variants that may find utility in synthetic biology.

PubMed: 33623032
DOI: 10.1038/s41467-021-21528-2

Experimental method

X-RAY DIFFRACTION (1.67 Å)