1mdj
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HIGH RESOLUTION SOLUTION NMR STRUCTURE OF MIXED DISULFIDE INTERMEDIATE BETWEEN HUMAN THIOREDOXIN (C35A, C62A, C69A, C73A) MUTANT AND A 13 RESIDUE PEPTIDE COMPRISING ITS TARGET SITE IN HUMAN NFKB (RESIDUES 56-68 OF THE P50 SUBUNIT OF NFKB)
OverviewOverview
BACKGROUND: Human thioredoxin is a 12 kDa cellular redox protein that, plays a key role in maintaining the redox environment of the cell. It has, recently been shown to be responsible for activating the DNA-binding, properties of the cellular transcription factor, NF kappa B, by reducing a, disulfide bond involving Cys62 of the p50 subunit. Using multidimensional, heteronuclear-edited and hetero-nuclear-filtered NMR spectroscopy, we have, solved the solution structure of a complex of human thioredoxin and a, 13-residue peptide extending from residues 56-68 of p50, representing a, kinetically stable mixed disulfide intermediate along the reaction, pathway. RESULTS: The NF kappa B peptide is located in a long boot-shaped, cleft on the surface of human thioredoxin delineated by the active-site, loop, helices alpha 2, alpha 3 and alpha 4, and strands beta 3 and beta 4., The peptide adopts a crescent-like conformation with a smooth 110 degrees, bend centered around residue 60 which permits it to follow the path of the, cleft. CONCLUSIONS: In addition to the intermolecular disulfide bridge, between Cys32 of human thioredoxin and Cys62 of the peptide, the complex, is stabilized by numerous hydrogen-bonding, electrostatic and hydrophobic, interactions which involve residues 57-65 of the NF kappa B peptide and, confer substrate specificity. These structural features permit one to, suggest the specificity requirements for human thioredoxin-catalyzed, disulfide bond reduction of proteins.
DiseaseDisease
Known disease associated with this structure: Ciliary dyskinesia, primary, 6 OMIM:[607421]
About this StructureAbout this Structure
1MDJ is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Solution structure of human thioredoxin in a mixed disulfide intermediate complex with its target peptide from the transcription factor NF kappa B., Qin J, Clore GM, Kennedy WM, Huth JR, Gronenborn AM, Structure. 1995 Mar 15;3(3):289-97. PMID:7788295
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