Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.5.1.4 (
deaminase
)
5,113
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Protozoa of the order Kinetoplastida differ from other organisms in their ability to conjugate glutathione (gamma-Glu-Cys-Gly) and spermidine to form trypanothione (N1,N8-bis(glutathionyl)spermidine), which is involved in maintaining intracellular thiol redox and in defense against oxidants. In this study, the genes from Crithidia fasciculata, Cf-GSS and Cf-
TRS
, which encode, respectively, glutathionylspermidine synthetase (EC 6.3.1.8) and trypanothione synthetase (EC 6.3.1.9) have been cloned and expressed. The deduced amino acid sequence of both Cf-GSS and Cf-
TRS
share 50% sequence similarity with the Escherichia coli glutathionylspermidine synthetase/
amidase
. Both genes are present as single copies in the C. fasciculata genome. When expressed in E. coli and Saccharomyces cerevisiae, neither protein was present in an active soluble form. However, thiol analysis of S. cerevisiae demonstrated that cells transformed with the Cf-GSS gene contained substantial amounts of glutathionylspermidine, whereas cells expressing both the Cf-GSS and Cf-
TRS
genes contained glutathionylspermidine and trypanothione, confirming that these genes encode the functional glutathionylspermidine and trypanothione synthetases from C. fasciculata. The translation products of Cf-GSS and Cf-
TRS
show significant homology to the
amidase
domain present in E. coli glutathionylspermidine synthetase, which can catalyze both synthesis and degradation of glutathionylspermidine. Glutathionylspermidine synthetase isolated from C. fasciculata was found to possess a similar
amidase
activity.
...
PMID:Cloning and characterization of the two enzymes responsible for trypanothione biosynthesis in Crithidia fasciculata. 967 55