The intrachain disulfide bridge is responsible of the unusual stability properties of novel acylphosphatase from Escherichia coli.
Acylphosphatase (AcP) activity in prokaryotes was classically attributed to some aspecific acid phosphatases. We identified an open reading frame for a putative AcP in the b0968 Escherichia coli gene and purified the recombinant enzyme after checking by RT-PCR that it was indeed expressed. EcoAcP has a predicted typical fold of the AcP family but displays a very low specific activity and a high structural stability differently from its mesophilic and similarly to its hyperthermophilic counterparts. Site directed mutagenesis suggests that, together with other structural features, the intrachain S-S bridge in EcoAcP is involved in a remarkable thermal and chemical stabilization of the protein without affecting its catalytic activity.
Ramazzotti
Matteo
M
Department of Biochemical Sciences, University of Florence, V.le Morgagni 50, 50134 Firenze, Italy.
Parrini
Claudia
C
Stefani
Massimo
M
Manao
Giampaolo
G
Degl'Innocenti
Donatella
D
D017766:Acid Anhydride Hydrolases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D004220:Disulfides / Q000378:metabolism*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011489:Protein Denaturation / Q000187:drug effects; D016415:Sequence Alignment; D013696:Temperature; D013816:Thermodynamics; D014508:Urea / Q000494:pharmacology; D000097024:Acylphosphatase
D017766:Acid Anhydride Hydrolases; D003545:Cysteine; D004220:Disulfides; D007527:Isoenzymes; D014508:Urea; D000097024:Acylphosphatase