4WUO

Structure of the E270A Mutant Isopropylmalate dehydrogenase from Thermus thermophilus in complex with IPM, Mn and NADH

Summary for 4WUO

• Entry DOI: 10.2210/pdb4wuo/pdb
• Related: 1HEX 2Y3Z 2Y40 2Y41 2Y42 4F7I
• Descriptor: 3-isopropylmalate dehydrogenase, 3-ISOPROPYLMALIC ACID, NICOTINAMIDE-ADENINE-DINUCLEOTIDE, ... (8 entities in total)
• Functional Keywords: isopropylmalate dehydrogenase, ipmdh, oxidoreductase, mutant
• Biological source: Thermus thermophilus
• Cellular location: Cytoplasm: Q5SIY4
• Total number of polymer chains: 2
• Total formula weight: 79200.71

Authors

Pallo, A.,Graczer, E.,Olah, J.,Szimler, T.,Konarev, P.V.,Svergun, D.I.,Merli, A.,Zavodszky, P.,Vas, M.,Weiss, M.S. (deposition date: 2014-11-03, release date: 2014-11-12, Last modification date: 2024-01-10)

Primary citation

Graczer, E.,Pallo, A.,Olah, J.,Szimler, T.,Konarev, P.V.,Svergun, D.I.,Merli, A.,Zavodszky, P.,Weiss, M.S.,Vas, M.
Glutamate 270 plays an essential role in K(+)-activation and domain closure of Thermus thermophilus isopropylmalate dehydrogenase.
Febs Lett., 589:240-245, 2015

PubMed Abstract: The mutant E270A of Thermus thermophilus 3-isopropylmalate dehydrogenase exhibits largely reduced (∼1%) catalytic activity and negligible activation by K(+) compared to the wild-type enzyme. A 3-4 kcal/mol increase in the activation energy of the catalysed reaction upon this mutation could also be predicted by QM/MM calculations. In the X-ray structure of the E270A mutant a water molecule was observed to take the place of K(+). SAXS and FRET experiments revealed the essential role of E270 in stabilisation of the active domain-closed conformation of the enzyme. In addition, E270 seems to position K(+) into close proximity of the nicotinamide ring of NAD(+) and the electron-withdrawing effect of K(+) may help to polarise the aromatic ring in order to aid the hydride-transfer.

PubMed: 25497013
DOI: 10.1016/j.febslet.2014.12.005

Experimental method

X-RAY DIFFRACTION (2.05 Å)