TY - JOUR
T1 - Biochemical characterization and homology modeling of a purine-specific ribonucleoside hydrolase from the archaeon Sulfolobus solfataricus
T2 - Insights into mechanisms of protein stabilization
AU - Porcelli, Marina
AU - Peluso, Iolanda
AU - Marabotti, Anna
AU - Facchiano, Angelo
AU - Cacciapuoti, Giovanna
PY - 2009/3/1
Y1 - 2009/3/1
N2 - We report the biochemical and structural characterization of the purine-specific ribonucleoside hydrolase from the archaeon Sulfolobus solfataricus (SsIAG-NH). SsIAG-NH is a homodimer of 70 kDa specific for adenosine, guanosine and inosine. SsIAG-NH is highly thermophilic and is characterized by extreme thermodynamic stability (Tm, 107 °C), kinetic stability and remarkable resistance to guanidinium chloride-induced unfolding. A disulfide bond that, on the basis of SDS-PAGE is positioned intersubunits, plays an important role in thermal stability. SsIAG-NH shares 43% sequence identity with the homologous pyrimidine-specific nucleoside hydrolase from S. solfataricus (SsCU-NH). The comparative sequence alignment of SsIAG-NH, SsCU-NH, purine non-specific nucleoside hydrolase from Crithidia fasciculata and purine-specific nucleoside hydrolase from Trypanosoma vivax shows that, only few changes in the base pocket are responsible for different substrate specificity of two S. solfataricus enzymes. The structure of SsIAG-NH predicted by homology modeling allows us to infer the role of specific residues in substrate specificity and thermostability.
AB - We report the biochemical and structural characterization of the purine-specific ribonucleoside hydrolase from the archaeon Sulfolobus solfataricus (SsIAG-NH). SsIAG-NH is a homodimer of 70 kDa specific for adenosine, guanosine and inosine. SsIAG-NH is highly thermophilic and is characterized by extreme thermodynamic stability (Tm, 107 °C), kinetic stability and remarkable resistance to guanidinium chloride-induced unfolding. A disulfide bond that, on the basis of SDS-PAGE is positioned intersubunits, plays an important role in thermal stability. SsIAG-NH shares 43% sequence identity with the homologous pyrimidine-specific nucleoside hydrolase from S. solfataricus (SsCU-NH). The comparative sequence alignment of SsIAG-NH, SsCU-NH, purine non-specific nucleoside hydrolase from Crithidia fasciculata and purine-specific nucleoside hydrolase from Trypanosoma vivax shows that, only few changes in the base pocket are responsible for different substrate specificity of two S. solfataricus enzymes. The structure of SsIAG-NH predicted by homology modeling allows us to infer the role of specific residues in substrate specificity and thermostability.
KW - Archaea
KW - Disulfide bonds
KW - Homology modeling
KW - Nucleoside hydrolase
KW - Nucleoside metabolism
KW - Sulfolobus solfataricus
KW - Thermostability
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U2 - 10.1016/j.abb.2008.12.005
DO - 10.1016/j.abb.2008.12.005
M3 - Article
C2 - 19121283
AN - SCOPUS:59849122116
VL - 483
SP - 55
EP - 65
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 1
ER -