Biochemical characterization and homology modeling of a purine-specific ribonucleoside hydrolase from the archaeon Sulfolobus solfataricus: Insights into mechanisms of protein stabilization |
| |
Authors: | Marina Porcelli Iolanda Peluso Angelo Facchiano |
| |
Institution: | a Dipartimento di Biochimica e Biofisica “F. Cedrangolo”, Seconda Università di Napoli, Via Costantinopoli 16, 80138, Napoli, Italy b Consorzio Interuniversitario Biostrutture e Biosistemi “INBB”, Viale Medaglie d’Oro 305, Roma, Italy c Istituto di Scienze dell’Alimentazione, Consiglio Nazionale delle Ricerche, Via Roma 64, 83100 Avellino, Italy |
| |
Abstract: | 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. |
| |
Keywords: | Nucleoside hydrolase Thermostability Nucleoside metabolism Homology modeling Disulfide bonds Sulfolobus solfataricus Archaea |
本文献已被 ScienceDirect 等数据库收录! |
|