Isolation and characterization of cDNA clones encoding a 32-kDa dense-granule antigen of Sarcocystis muris (Apicomplexa).
A monoclonal antibody (2F4) directed against a 32-kDa dense-granule antigen of Sarcocystis muris cyst merozoites (bradyzoites) was used to screen a lambda ZAP cDNA expression library. A clone with an insert of 1.4 kb in length (DG 32/1) was isolated. A fusion protein derived from bacteria harbouring the recombinant plasmid DG 32/1 reacted with monoclonal antibody (mAb) 2F4. Southern blot hybridization suggests that the gene is present as a single copy. On Northern blots, a single mRNA species of 1.8 kb was detected by a cDNA-derived probe. In addition, we isolated a full-length clone (DG 32/PH1) by screening the cDNA library with a non-radioactive-labelled cDNA probe. The nucleotide sequence of DG 32/PH1 comprises 1.57 kb. It contains an open reading frame of 882 bp with a coding capacity of approximately 32 kDa. The hypothetical polypeptide consists of a putative N-terminal signal peptide and the mature protein sequence. The occurrence of an N-terminal signal sequence is consistent with the observation that the 32-kDa protein of S. muris is secreted from the dense granules.
Lehrstuhl für Biologie der Mikroorganismen, Arbeitsgruppe Molekulare Genetik, Ruhr-Universität Bochum, Germany.
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Freyer
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Eschenbacher
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Mehlhorn
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W
Rueger
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry* / Q000235:genetics*; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D003001:Cloning, Molecular; D018076:DNA, Complementary; D016054:DNA, Protozoan / Q000235:genetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D015388:Organelles / Q000276:immunology; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics*; D012522:Sarcocystis / Q000235:genetics* / Q000276:immunology*; D017422:Sequence Analysis, DNA
D000953:Antigens, Protozoan; C114436:DG 32 protein, Sarcocystis muris; D018076:DNA, Complementary; D016054:DNA, Protozoan; D015800:Protozoan Proteins