title: Identification of papain-like cysteine proteases from the bovine piroplasm Babesia bigemina and evolutionary relationship of piroplasms C1 family of cysteine proteases.
abstract: Papain-like cysteine proteases have been shown to have essential roles in parasitic protozoa and are under study as promising drug targets. Five genes were identified by sequence similarity search to be homologous to the cysteine protease family in the ongoing Babesia bigemina genome sequencing project database and were compared with the annotated genes from the complete bovine piroplasm genomes of Babesia bovis, Theileria annulata, and Theileria parva. Multiple genome alignments and sequence analysis were used to evaluate the molecular evolution events that occurred in the C1 family of cysteine proteases in these piroplasms of veterinary importance. BbiCPL1, one of the newly identified cysteine protease genes in the B. bigemina genome was expressed in Escherichia coli and shows activity against peptide substrates. Considerable differences were observed in the cysteine protease family between Babesia and Theileria genera, and this may partially explain the diverse infection mechanisms of these tick-borne diseases.
authors.affiliation: Unidade de Tecnologias de Proteínas e Anticorpos Monoclonais, Instituto de Higiene e Medicina Tropical, Estrada do Paço do Lumiar 22, 1649-038 Lisboa, Portugal. tmlmartins@gmail.com
authors.forename: Tiago M
authors.initials: TM
authors.lastname: Martins
authors.forename: Virgílio E
authors.initials: VE
authors.lastname: do Rosário
authors.forename: Ana
authors.initials: A
authors.lastname: Domingos
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001403:Babesia / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D001404:Babesiosis / Q000469:parasitology / Q000662:veterinary*; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D003001:Cloning, Molecular; D057056:Cysteine Proteases / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D019143:Evolution, Molecular; D005786:Gene Expression Regulation / Q000235:genetics; D018503:Genome, Protozoan; D010802:Phylogeny; D016415:Sequence Alignment / Q000662:veterinary; D016794:Theileria / Q000145:classification / Q000201:enzymology / Q000235:genetics
chemical_list: D057056:Cysteine Proteases