1I5G

TRYPAREDOXIN II COMPLEXED WITH GLUTATHIONYLSPERMIDINE

Summary for 1I5G

• Entry DOI: 10.2210/pdb1i5g/pdb
• Related: 1FG4
• Descriptor: TRYPAREDOXIN II, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL, GLUTATHIONYLSPERMIDINE, ... (4 entities in total)
• Functional Keywords: tryparedoxin, electron transport
• Biological source: Crithidia fasciculata
• Total number of polymer chains: 1
• Total formula weight: 16780.21

Authors

Hofmann, B.,Budde, H.,Bruns, K.,Guerrero, S.A.,Kalisz, H.M.,Menge, U.,Montemartini, M.,Nogoceke, E.,Steinert, P.,Wissing, J.B.,Flohe, L.,Hecht, H.-J. (deposition date: 2001-02-27, release date: 2001-03-14, Last modification date: 2024-11-20)

Primary citation

Hofmann, B.,Budde, H.,Bruns, K.,Guerrero, S.A.,Kalisz, H.M.,Menge, U.,Montemartini, M.,Nogoceke, E.,Steinert, P.,Wissing, J.B.,Flohe, L.,Hecht, H.J.
Structures of tryparedoxins revealing interaction with trypanothione.
Biol.Chem., 382:459-471, 2001

PubMed Abstract: 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.

PubMed: 11347894
DOI: 10.1515/BC.2001.056

Experimental method

X-RAY DIFFRACTION (1.4 Å)