1ezk
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(New page: 200px<br /><applet load="1ezk" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ezk, resolution 1.9Å" /> '''Crystal structure of ...)
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Revision as of 20:56, 24 November 2007
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Crystal structure of recombinant tryparedoxin I
Overview
Tryparedoxins (TXNs) catalyse the reduction of peroxiredoxin-type, peroxidases by the bis-glutathionyl derivative of spermidine, trypanothione, and are relevant to hydroperoxide detoxification and, virulence of trypanosomes. The 3D-structures of the following, tryparedoxins are presented: authentic tryparedoxin1 of Crithidia, fasciculata, CfTXN1; the his-tagged recombinant protein, CfTXN1H6; reduced, and oxidised CfTXN2, and an alternative substrate derivative of the mutein, CfTXN2H6-Cys44Ser. Cys41 (Cys40 in TXN1) of the active site motif, 40-WCPPCR-45 proved to be the only solvent-exposed redox active residue in, CfTXN2. In reduced TXNs, its nucleophilicity is increased by a network of, hydrogen bonds. In oxidised TXNs it can be attacked by the thiol of the, 1N-glutathionyl residue of trypanothione, as evidenced by the structure of, 1N-glutathionylspermidine-derivatised CfTXN2H6-Cys44Ser. Modelling, suggests Arg45 (44), Glu73 (72), the Ile110 (109) cis-Pro111 (110)-bond, and Arg129 (128) to be involved in the binding of trypanothione to CfTXN2, (CfTXN1). The model of TXN-substrate interaction is consistent with, functional characteristics of known and newly designed muteins, (CfTXN2H6-Arg129Asp and Glu73Arg) and the 1N-glutathionyl-spermidine, binding in the CfTXN2H6-Cys44Ser structure.
About this Structure
1EZK is a Single protein structure of sequence from Crithidia fasciculata. Full crystallographic information is available from OCA.
Reference
Structures of tryparedoxins revealing interaction with trypanothione., Hofmann B, Budde H, Bruns K, Guerrero SA, Kalisz HM, Menge U, Montemartini M, Nogoceke E, Steinert P, Wissing JB, Flohe L, Hecht HJ, Biol Chem. 2001 Mar;382(3):459-71. PMID:11347894
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