Structure-function analysis of yeast Grx5 monothiol glutaredoxin defines essential amino acids for the function of the protein

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2002Author
Polaina, Julio
Rodríguez Manzanaque, Maria Teresa
Suggested citation
Bellí i Martínez, Gemma;
Polaina, Julio;
Tamarit Sumalla, Jordi;
Torre Ruiz, M. A. de la;
Rodríguez Manzanaque, Maria Teresa;
Ros Salvador, Joaquim;
Herrero Perpiñán, Enrique;
.
(2002)
.
Structure-function analysis of yeast Grx5 monothiol glutaredoxin defines essential amino acids for the function of the protein.
The Journal of Biological Chemistry, 2002, vol. 277, núm 40, p. 37590-37596.
https://doi.org/10.1074/jbc.M201688200.
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Show full item recordAbstract
Grx5 defines a family of yeast monothiol glutaredox-
ins that also includes Grx3 and Grx4. All three proteins
display significant sequence homology with proteins
found from bacteria to humans. Grx5 is involved in iron/
sulfur cluster assembly at the mitochondria, but the
function of Grx3 and Grx4 is unknown. Three-dimen-
sional modeling based on known dithiol glutaredoxin
structures predicted a thioredoxin fold structure for
Grx5. Positionally conserved amino acids in this glu-
taredoxin family were replaced in Grx5, and the effect
on the biological function of the protein has been tested.
For all changes studied, there was a correlation between
the effects on several different phenotypes: sensitivity
to oxidants, constitutive protein oxidation, ability for
respiratory growth, auxotrophy for a number of amino
acids, and iron accumulation. Cys60 and Gly61 are essen-
tial for Grx5 function, whereas other single or double
substitutions in the same region had no phenotypic ef-
fects. Gly115 and Gly116 could be important for the for-
mation of a glutathione cleft on the Grx5 surface, in
contrast to adjacent Cys117. Substitution of Phe50 alters
the -sheet in the thioredoxin fold structure and inhib-
its Grx5 function. None of the substitutions tested affect
the structure at a significant enough level to reduce
protein stability.