Isolation, sequence and molecular karyotype analysis of the actin gene of Cryptosporidium parvum.
Actin is an ubiquitous and highly conserved microfilament protein which is hypothesized to play a mechanical, force-generating role in the unusual gliding motility of sporozoan zoites and in their active penetration of host cells. We have identified and isolated an actin gene from a Cryptosporidium parvum genomic DNA library using a chicken beta-actin cDNA as an hybridization probe. The nucleotide sequences of two overlapping recombinant clones were identical and the amino acid sequence deduced from the single open reading frame was 85 % identical to the P. falciparum actin I and human gamma-actin proteins. The predicted 42 106-Da Cryptosporidium actin contains 376 amino acids and is encoded by a single-copy gene which contains no introns. The nucleic acid coding sequence is 72% biased to the use of A or T in the third position of codons. Chromosome-sized DNA released from intact C. parvum oocysts was resolved by OFAGE into 5 discrete ethidium bromide-staining DNAs ranging in size from 900 to 1400 kb; the cloned C. parvum actin gene hybridized to a single chromosomal DNA of approximately 1200 kb.
Kim
K
K
Parasitology Laboratory, San Francisco General Hospital, CA.
Goozé
L
L
Petersen
C
C
Gut
J
J
Nelson
R G
RG
D000199:Actins / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D003062:Codon; D016785:Cryptosporidium parvum / Q000235:genetics*; D016054:DNA, Protozoan; D007621:Karyotyping; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D016415:Sequence Alignment
D000199:Actins; D003062:Codon; D016054:DNA, Protozoan