4QL7

Crystal structure of C-terminus truncated Alkylhydroperoxide Reductase subunit C (AhpC1-172) from E. coli

Summary for 4QL7

• Entry DOI: 10.2210/pdb4ql7/pdb
• Related: 4QL9
• Descriptor: Alkylhydroperoxide Reductase subunit C (1 entity in total)
• Functional Keywords: oxidoreductase, peroxiredoxin, ahpc
• Biological source: Escherichia coli
• Total number of polymer chains: 5
• Total formula weight: 96598.53

Authors

Kamariah, N.,Gruber, G.,Eisenhaber, F.,Eisenhaber, B. (deposition date: 2014-06-11, release date: 2014-09-24, Last modification date: 2023-11-08)

Primary citation

Dip, P.V.,Kamariah, N.,Nartey, W.,Beushausen, C.,Kostyuchenko, V.A.,Ng, T.S.,Lok, S.M.,Saw, W.G.,Eisenhaber, F.,Eisenhaber, B.,Gruber, G.
Key roles of the Escherichia coli AhpC C-terminus in assembly and catalysis of alkylhydroperoxide reductase, an enzyme essential for the alleviation of oxidative stress.
Biochim.Biophys.Acta, 1837:1932-1943, 2014

PubMed Abstract: 2-Cys peroxiredoxins (Prxs) are a large family of peroxidases, responsible for antioxidant function and regulation in cell signaling, apoptosis and differentiation. The Escherichia coli alkylhydroperoxide reductase (AhpR) is a prototype of the Prxs-family, and is composed of an NADH-dependent AhpF reductase (57 kDa) and AhpC (21 kDa), catalyzing the reduction of H2O2. We show that the E. coli AhpC (EcAhpC, 187 residues) forms a decameric ring structure under reduced and close to physiological conditions, composed of five catalytic dimers. Single particle analysis of cryo-electron micrographs of C-terminal truncated (EcAhpC1 -172 and EcAhpC1 -182) and mutated forms of EcAhpC reveals the loss of decamer formation, indicating the importance of the very C-terminus of AhpC in dimer to decamer transition. The crystallographic structures of the truncated EcAhpC1 -172 and EcAhpC1 -182 demonstrate for the first time that, in contrast to the reduced form, the very C-terminus of the oxidized EcAhpC is oriented away from the AhpC dimer interface and away from the catalytic redox-center, reflecting structural rearrangements during redox-modulation and -oligomerization. Furthermore, using an ensemble of different truncated and mutated EcAhpC protein constructs the importance of the very C-terminus in AhpC activity and in AhpC-AhpF assembly has been demonstrated.

PubMed: 25193562
DOI: 10.1016/j.bbabio.2014.08.007

Experimental method

X-RAY DIFFRACTION (3.75 Å)