Identification and characterisation of a novel acylpeptide hydrolase from Sulfolobus solfataricus: structural and functional insights.
A novel acylpeptide hydrolase, named APEH-3(Ss), was isolated from the hypertermophilic archaeon Sulfolobus solfataricus. APEH is a member of the prolyl oligopeptidase family which catalyzes the removal of acetylated amino acid residues from the N terminus of oligopeptides. The purified enzyme shows a homotrimeric structure, unique among the associate partners of the APEH cluster and, in contrast to the archaeal APEHs which show both exo/endo peptidase activities, it appears to be a "true" aminopeptidase as exemplified by its mammalian counterparts, with which it shares a similar substrate specificity. Furthermore, a comparative study on the regulation of apeh gene expression, revealed a significant but divergent alteration in the expression pattern of apeh-3(Ss) and apeh(Ss) (the gene encoding the previously identified APEH(Ss) from S. solfataricus), which is induced in response to various stressful growth conditions. Hence, both APEH enzymes can be defined as stress-regulated proteins which play a complementary role in enabling the survival of S. solfataricus cells under different conditions. These results provide new structural and functional insights into S. solfataricus APEH, offering a possible explanation for the multiplicity of this enzyme in Archaea.
Institute of Protein Biochemistry, National Research Council (CNR-IBP), Naples, Italy.
Marta
M
Gogliettino
Marco
M
Balestrieri
Ennio
E
Cocca
Sabrina
S
Mucerino
Mose
M
Rossi
Mauro
M
Petrillo
Emanuela
E
Mazzella
Gianna
G
Palmieri
D000595:Amino Acid Sequence; D019848:Gene Expression Regulation, Archaeal; D006358:Hot Temperature; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D017433:Protein Structure, Secondary; D013379:Substrate Specificity; D048229:Sulfolobus solfataricus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics
D010447:Peptide Hydrolases; C038220:acylaminoacyl-peptidase