1r7h
From Proteopedia
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NrdH-redoxin of Corynebacterium ammoniagenes forms a domain-swapped dimer
Overview
NrdH-redoxins constitute a family of small redox proteins, which contain a, conserved CXXC sequence motif, and are characterized by a, glutaredoxin-like amino acid sequence but a thioredoxin-like activity, profile. Here we report the structure of Corynebacterium ammoniagenes NrdH, at 2.7 A resolution, determined by molecular replacement using E. coli, NrdH as model. The structure is the first example of a domain-swapped, dimer from the thioredoxin family. The domain-swapped structure is formed, by an inter-chain two-stranded anti-parallel beta-sheet and is stabilized, by electrostatic interactions at the dimer interface. Size exclusion, chromatography, and MALDI-ESI experiments revealed however, that the, protein exists as a monomer in solution. Similar to E. coli NrdH-redoxin, and thioredoxin, C. ammoniagenes NrdH-redoxin has a wide hydrophobic, pocket at the surface that could be involved in binding to thioredoxin, reductase. However, the loop between alpha2 and beta3, which is, complementary to a crevice in the reductase in the thioredoxin-thioredoxin, reductase complex, is the hinge for formation of the swapped dimer in C., ammoniagenes NrdH-redoxin. C. ammoniagenes NrdH-redoxin has the highly, conserved sequence motif W61-S-G-F-R-P-[DE]67 which is unique to the, NrdH-redoxins and which determines the orientation of helix alpha3. An, extended hydrogen-bond network, similar to that in E. coli NrdH-redoxin, determines the conformation of the loop formed by the conserved motif.
About this Structure
1R7H is a Single protein structure of sequence from Corynebacterium ammoniagenes. Full crystallographic information is available from OCA.
Reference
NrdH-redoxin of Corynebacterium ammoniagenes forms a domain-swapped dimer., Stehr M, Lindqvist Y, Proteins. 2004 May 15;55(3):613-9. PMID:15103625
Page seeded by OCA on Sat Nov 24 22:17:35 2007
