4PW3

Crystal structure of the sulfite dehydrogenase SorT from Sinorhizobium meliloti

Summary for 4PW3

• Entry DOI: 10.2210/pdb4pw3/pdb
• Related: 4PW9 4PWA
• Descriptor: Putative sulfite oxidase, (MOLYBDOPTERIN-S,S)-OXO-MOLYBDENUM, 1,2-ETHANEDIOL, ... (4 entities in total)
• Functional Keywords: sulfite oxidase, sulfite dehydrogenase, molybdopterin, oxidoreductase
• Biological source: Sinorhizobium meliloti (Ensifer meliloti)
• Total number of polymer chains: 4
• Total formula weight: 160355.97

Authors

McGrath, A.P.,Maher, M.J. (deposition date: 2014-03-18, release date: 2015-06-03, Last modification date: 2023-09-20)

Primary citation

McGrath, A.P.,Laming, E.L.,Casas Garcia, G.P.,Kvansakul, M.,Guss, J.M.,Trewhella, J.,Calmes, B.,Bernhardt, P.V.,Hanson, G.R.,Kappler, U.,Maher, M.J.
Structural basis of interprotein electron transfer in bacterial sulfite oxidation.
Elife, 4:e09066-e09066, 2015

PubMed Abstract: Interprotein electron transfer underpins the essential processes of life and relies on the formation of specific, yet transient protein-protein interactions. In biological systems, the detoxification of sulfite is catalyzed by the sulfite-oxidizing enzymes (SOEs), which interact with an electron acceptor for catalytic turnover. Here, we report the structural and functional analyses of the SOE SorT from Sinorhizobium meliloti and its cognate electron acceptor SorU. Kinetic and thermodynamic analyses of the SorT/SorU interaction show the complex is dynamic in solution, and that the proteins interact with Kd = 13.5 ± 0.8 μM. The crystal structures of the oxidized SorT and SorU, both in isolation and in complex, reveal the interface to be remarkably electrostatic, with an unusually large number of direct hydrogen bonding interactions. The assembly of the complex is accompanied by an adjustment in the structure of SorU, and conformational sampling provides a mechanism for dissociation of the SorT/SorU assembly.

PubMed: 26687009
DOI: 10.7554/eLife.09066

Experimental method

X-RAY DIFFRACTION (2.35 Å)