Characterization of a conserved extrachromosomal element isolated from the avian malarial parasite Plasmodium gallinaceum

We have identified a conserved, repeated, and highly transcribed DNA element from the avian malarial parasite Plasmodium gallinaceum. The element produced multiple transcripts in both zygotes and asexual blood stages of this parasite. It was found to be highly conserved in all of five malarial species tested and hybridized at reduced stringency to other members of the phylum Apicomplexa, including the genera Babesia, Eimeria, Toxoplasma, and Theileria. The copy number of the element was about 15, and it had a circularly permuted restriction map with a repeat unit length of about 6.2 kilobases. It could be separated from the main genomic DNA by using sucrose gradients and agarose gels, and it migrated separately from the recognized Plasmodium chromosomes on pulse-field gels. In the accompanying paper (S. M. Aldritt, J. T. Joseph, and D. F. Wirth, Mol. Cell. Biol. 9:3614-3620, 1989), evidence is presented that element contains the mitochondrial genes for the protein cytochrome b and a fragment of the large rRNA. We postulate that this element is an episome in the mitochondria of the obligate parasites belonging to the phylum Apicomplexa.

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Sequence identification of cytochrome b in Plasmodium gallinaceum.

Molecular and Cellular Biology ◽

10.1128/mcb.9.9.3614 ◽

1989 ◽

Vol 9 (9) ◽

pp. 3614-3620 ◽

Cited By ~ 47

Author(s):

S M Aldritt ◽

J T Joseph ◽

D F Wirth

Keyword(s):

Cytochrome B ◽

Open Reading Frame ◽

Malarial Parasite ◽

Plasmodium Gallinaceum ◽

Primary Transcript ◽

Present Evidence ◽

Reading Frame ◽

Sequence Identification ◽

Parasite Plasmodium ◽

Extrachromosomal Element

We have identified a gene that encodes the polypeptide cytochrome b in the avian malarial parasite Plasmodium gallinaceum. The gene containing the open reading frame was found to be located on a 6.2-kilobase multimeric extrachromosomal element. The amino acid translation from this gene demonstrated significant similarities to cytochrome b sequences from yeast, mammal, and fungus genomes. We present evidence that the P. gallinaceum cytochrome b transcript is part of a larger primary transcript from the element that is subsequently processed. The message for P. gallinaceum cytochrome b was found to be 1.2 kilobases in size. This is the first report identifying a mitochondrial nucleic acid sequence in malaria-causing organisms and suggests that a functional cytochrome system may exist in these parasites.

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Sequence identification of cytochrome b in Plasmodium gallinaceum

Molecular and Cellular Biology ◽

10.1128/mcb.9.9.3614-3620.1989 ◽

1989 ◽

Vol 9 (9) ◽

pp. 3614-3620

Author(s):

S M Aldritt ◽

J T Joseph ◽

D F Wirth

Keyword(s):

Cytochrome B ◽

Open Reading Frame ◽

Malarial Parasite ◽

Plasmodium Gallinaceum ◽

Primary Transcript ◽

Present Evidence ◽

Reading Frame ◽

Sequence Identification ◽

Parasite Plasmodium ◽

Extrachromosomal Element

We have identified a gene that encodes the polypeptide cytochrome b in the avian malarial parasite Plasmodium gallinaceum. The gene containing the open reading frame was found to be located on a 6.2-kilobase multimeric extrachromosomal element. The amino acid translation from this gene demonstrated significant similarities to cytochrome b sequences from yeast, mammal, and fungus genomes. We present evidence that the P. gallinaceum cytochrome b transcript is part of a larger primary transcript from the element that is subsequently processed. The message for P. gallinaceum cytochrome b was found to be 1.2 kilobases in size. This is the first report identifying a mitochondrial nucleic acid sequence in malaria-causing organisms and suggests that a functional cytochrome system may exist in these parasites.

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Comparison of protein repeat classifications based on structure and sequence families

Biochemical Society Transactions ◽

10.1042/bst20150079 ◽

2015 ◽

Vol 43 (5) ◽

pp. 832-837 ◽

Cited By ~ 8

Author(s):

Lisanna Paladin ◽

Silvio C.E. Tosatto

Keyword(s):

Tandem Repeats ◽

Repeat Unit ◽

Unit Length ◽

Detailed Comparison ◽

Structural Classification ◽

Evolutionarily Conserved ◽

Repeat Unit Length ◽

One To One ◽

Leucine Rich Repeats ◽

Structural Classes

Tandem repeats (TR) in proteins are common in nature and have several unique functions. They come in various forms that are frequently difficult to recognize from a sequence. A previously proposed structural classification has been recently implemented in the RepeatsDB database. This defines five main classes, mainly based on repeat unit length, with subclasses representing specific folds. Sequence-based classifications, such as Pfam, provide an alternative classification based on evolutionarily conserved repeat families. Here, we discuss a detailed comparison between the structural classes in RepeatsDB and the corresponding Pfam repeat families and clans. Most instances are found to map one-to-one between structure and sequence. Some notable exceptions such as leucine-rich repeats (LRRs) and α-solenoids are discussed.

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Characterization of adenosine deaminase from the malarial parasite, Plasmodium lophurae, and its host cell, the duckling erythrocyte

Biochemical Pharmacology ◽

10.1016/0006-2952(83)90662-7 ◽

1983 ◽

Vol 32 (1) ◽

pp. 115-122 ◽

Cited By ~ 13

Author(s):

Christina M. Schimandle ◽

Irwin W. Sherman

Keyword(s):

Host Cell ◽

Adenosine Deaminase ◽

Malarial Parasite ◽

Plasmodium Lophurae ◽

Parasite Plasmodium

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RAD1 Controls the Meiotic Expansion of the Human HRAS1 Minisatellite in Saccharomyces cerevisiae

Molecular and Cellular Biology ◽

10.1128/mcb.22.3.953-964.2002 ◽

2002 ◽

Vol 22 (3) ◽

pp. 953-964 ◽

Cited By ~ 17

Author(s):

Peter A. Jauert ◽

Sharon N. Edmiston ◽

Kathleen Conway ◽

David T. Kirkpatrick

Keyword(s):

Saccharomyces Cerevisiae ◽

Repetitive Dna ◽

Hot Spot ◽

Repeat Unit ◽

Unit Length ◽

Wild Type ◽

Strand Breaks ◽

Tract Length ◽

Sequence Composition ◽

Repeat Unit Length

ABSTRACT Minisatellite DNA is repetitive DNA with a repeat unit length from 15 to 100 bp. While stable during mitosis, it destabilizes during meiosis, altering both in length and in sequence composition. The basis for this instability is unknown. To investigate the factors controlling minisatellite stability, a minisatellite sequence 3′ of the human HRAS1 gene was introduced into the Saccharomyces cerevisiae genome, replacing the wild-type HIS4 promoter. The minisatellite tract exhibited the same phenotypes in yeast that it exhibited in mammalian systems. The insertion stimulated transcription of the HIS4 gene; mRNA production was detected at levels above those seen with the wild-type promoter. The insertion stimulated meiotic recombination and created a hot spot for initiation of double-strand breaks during meiosis in the regions immediately flanking the repetitive DNA. The tract length altered at a high frequency during meiosis, and both expansions and contractions in length were detected. Tract expansion, but not contraction, was controlled by the product of the RAD1 gene. RAD1 is the first gene identified that controls specifically the expansion of minisatellite tracts. A model for tract length alteration based on these results is presented.

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