2UZA

CRYSTAL STRUCTURE OF THE FREE RADICAL INTERMEDIATE OF PYRUVATE:FERREDOXIN OXIDOREDUCTASE FROM DESULFOVIBRIO AFRICANUS

Summary for 2UZA

• Entry DOI: 10.2210/pdb2uza/pdb
• Related: 1B0P 1KEK 2C3M 2C3O 2C3P 2C3U 2C3Y 2C42 2PDA
• Descriptor: PYRUVATE FERREDOXIN OXIDOREDUCTASE, IRON/SULFUR CLUSTER, 2-ACETYL-THIAMINE DIPHOSPHATE, ... (7 entities in total)
• Functional Keywords: tpp-dependent enzyme, pyruvate catabolism, oxidoreductase, electron transport
• Biological source: DESULFOVIBRIO AFRICANUS
• Total number of polymer chains: 2
• Total formula weight: 270669.14

Authors

Chabriere, E.,Cavazza, C.,Contreras-Martel, C.,Fontecilla-Camps, J.C. (deposition date: 2007-04-27, release date: 2008-05-20, Last modification date: 2024-10-23)

Primary citation

Cavazza, C.,Contreras-Martel, C.,Pieulle, L.,Chabriere, E.,Hatchikian, E.C.,Fontecilla-Camps, J.C.
Flexibility of thiamine diphosphate revealed by kinetic crystallographic studies of the reaction of pyruvate-ferredoxin oxidoreductase with pyruvate.
Structure, 14:217-224, 2006

PubMed Abstract: Pyruvate-ferredoxin oxidoreductases (PFOR) are unique among thiamine pyrophosphate (ThDP)-containing enzymes in giving rise to a rather stable cofactor-based free-radical species upon the decarboxylation of their first substrate, pyruvate. We have obtained snapshots of unreacted and partially reacted (probably as a tetrahedral intermediate) pyruvate-PFOR complexes at different time intervals. We conclude that pyruvate decarboxylation involves very limited substrate-to-product movements but a significant displacement of the thiazolium moiety of ThDP. In this respect, PFOR seems to differ substantially from other ThDP-containing enzymes, such as transketolase and pyruvate decarboxylase. In addition, exposure of PFOR to oxygen in the presence of pyruvate results in significant inhibition of catalytic activity, both in solution and in the crystals. Examination of the crystal structure of inhibited PFOR suggests that the loss of activity results from oxime formation at the 4' amino substituent of the pyrimidine moiety of ThDP.

PubMed: 16472741
DOI: 10.1016/j.str.2005.10.013

Experimental method

X-RAY DIFFRACTION (2.42 Å)