title: Characterization of S-adenosylhomocysteine hydrolase from Cryptosporidium parvum.
abstract: The S-adenosylhomocysteine hydrolase from the apicomplexan Cryptosporidium parvum (CpSAHH) has been characterized. CpSAHH is a single-copy, intronless gene of 1479 bp encoding a protein of 493 amino acids with a molecular mass of 55.6 kDa. Reverse transcriptase-polymerase chain reaction analysis confirmed that CpSAHH is expressed both in intracellular stages (in C. parvum-infected HCT-8 cells 24 h after infection) and in sporozoites. CpSAHH was expressed in Escherichia coli TB1 cells as a fusion with maltose-binding protein. The recombinant fusion was cleaved by Factor Xa and the enzymatic activity of both the fusion protein and the purified separated CpSAHH was measured. The enzymatic activity of CpSAHH was inhibited by d-eritadenine, S-DHPA and Ara-A.
authors.affiliation: Department of Tropical Medicine, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic. ctrnacta@yahoo.com
authors.forename: Vlasta
authors.initials: V
authors.lastname: Ctrnáctá
authors.forename: Frantisek
authors.initials: F
authors.lastname: Stejskal
authors.forename: Janet S
authors.initials: JS
authors.lastname: Keithly
authors.forename: Ivan
authors.initials: I
authors.lastname: Hrdý
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D043383:Adenosylhomocysteinase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D016785:Cryptosporidium parvum / Q000201:enzymology* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental; D007438:Introns; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D016053:RNA, Protozoan / Q000096:biosynthesis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014740:Vidarabine / Q000494:pharmacology
chemical_list: D012333:RNA, Messenger; D016053:RNA, Protozoan; D011993:Recombinant Fusion Proteins; C100029:eritadenine; C016391:9-(2,3-dihydroxypropyl)adenine; D043383:Adenosylhomocysteinase; D014740:Vidarabine; D000225:Adenine