Isolation of putative cysteine protease genes of Ostertagia ostertagi.
Recombinant phage containing putative Ostertagia ostertagi cysteine protease genes have been isolated from a lambda EMBL-3:genomic DNA library using a Haemonchus contortus cathepsin B-like cysteine protease cDNA as hybridization probe. Restriction enzyme maps of the phages suggest that they identify at least 3 genes, 2 of which appear to be linked in tandem. The complete nucleotide sequence of one gene, CP-1, was determined. The CP-1 gene appears to be organized into 12 exons than span 4.5 kb of DNA. The number and sizes of the exons are essentially identical to those in the H. contortus AC-2 cysteine protease gene. Partial nucleotide sequences obtained for a second O. ostertagi gene, CP-3, revealed a similar organization for exons 8-12 in this gene. Like other cathepsin B-like cysteine proteases, CP-1 appears to be synthesized initially as a preproprotein that is proteolytically processed to its mature form. The amino acid identity between the presumptive CP-1 and CP-3 proteins is 66%, which is similar to the level of homology between the presumed mature protein regions of CP-1 and AC-2. Amino acid identity between CP-1 and AC-2 is greatest in the mature protein region and lowest in the signal sequence and propeptide regions. The CP-3 protein appears to be most closely related to the H. contortus AC-5 protein. CP-1 and CP-3 display significantly greater homology to H. contortus cysteine proteases than they do to human cathepsin B or the Sm31 cysteine protease of Schistosoma mansoni (about 40% identity with each).
Pratt
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Synergen, Inc., Boulder, CO 80301.
Boisvenue
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Cox
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003546:Cysteine Endopeptidases / Q000235:genetics*; D004247:DNA / Q000235:genetics; D005091:Exons; D017238:Genes, Helminth; D006189:Haemonchus / Q000201:enzymology / Q000235:genetics; D007438:Introns; D008969:Molecular Sequence Data; D005810:Multigene Family; D010028:Ostertagia / Q000201:enzymology* / Q000235:genetics*; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
D004247:DNA; D003546:Cysteine Endopeptidases