The Toxoplasma gondii plastid replication and repair enzyme complex, PREX

A Mukhopadhyay, C-Y Chen, C Doerig, F L Henriquez, C W Roberts, M P Barrett, Craig Roberts

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

A plastid-like organelle, the apicoplast, is essential to the majority of medically and veterinary important apicomplexan protozoa including Toxoplasma gondii and Plasmodium. The apicoplast contains multiple copies of a 35 kb genome, the replication of which is dependent upon nuclear-encoded proteins that are imported into the organelle. In P. falciparum an unusual multi-functional gene, pfprex, was previously identified and inferred to encode a protein with DNA primase, DNA helicase and DNA polymerase activities. Herein, we report the presence of a prex orthologue in T. gondii. The protein is predicted to have a bi-partite apicoplast targeting sequence similar to that demonstrated on the PfPREX polypeptide, capable of delivering marker proteins to the apicoplast. Unlike the P. falciparum gene that is devoid of introns, the T. gondii prex gene carries 19 introns, which are spliced to produce a contiguous mRNA. Bacterial expression of the polymerase domain reveals the protein to be active. Consistent with the reported absence of a plastid in Cryptosporidium species, in silico analysis of their genomes failed to demonstrate an orthologue of prex. These studies indicate that prex is conserved across the plastid-bearing apicomplexans and may play an important role in the replication of the plastid genome.

LanguageEnglish
Pages747-755
Number of pages9
JournalParasitology
Volume136
Issue number7
DOIs
Publication statusPublished - Jun 2009

Fingerprint

Apicoplasts
apicoplasts
Plastids
Toxoplasma
Toxoplasma gondii
plastids
Enzymes
enzymes
organelles
introns
proteins
Organelles
Introns
nuclear-encoded proteins
DNA helicases
Plastid Genomes
genome
genes
DNA Primase
Genome

Keywords

  • animals
  • DNA helicases
  • DNA primase
  • DNA replication
  • DNA, protozoan
  • DNA-directed DNA polymerase
  • exons
  • genome, protozoan
  • introns
  • mice
  • mice, inbred BALB C
  • molecular sequence data
  • multienzyme eomplexes
  • plastids
  • protozoan proteins
  • sequence analysis, DNA
  • toxoplasma

Cite this

Mukhopadhyay, A., Chen, C-Y., Doerig, C., Henriquez, F. L., Roberts, C. W., Barrett, M. P., & Roberts, C. (2009). The Toxoplasma gondii plastid replication and repair enzyme complex, PREX. Parasitology, 136(7), 747-755. https://doi.org/10.1017/S0031182009006027
Mukhopadhyay, A ; Chen, C-Y ; Doerig, C ; Henriquez, F L ; Roberts, C W ; Barrett, M P ; Roberts, Craig. / The Toxoplasma gondii plastid replication and repair enzyme complex, PREX. In: Parasitology. 2009 ; Vol. 136, No. 7. pp. 747-755.
@article{df974fa308dc4f398e1f61b5a059513a,
title = "The Toxoplasma gondii plastid replication and repair enzyme complex, PREX",
abstract = "A plastid-like organelle, the apicoplast, is essential to the majority of medically and veterinary important apicomplexan protozoa including Toxoplasma gondii and Plasmodium. The apicoplast contains multiple copies of a 35 kb genome, the replication of which is dependent upon nuclear-encoded proteins that are imported into the organelle. In P. falciparum an unusual multi-functional gene, pfprex, was previously identified and inferred to encode a protein with DNA primase, DNA helicase and DNA polymerase activities. Herein, we report the presence of a prex orthologue in T. gondii. The protein is predicted to have a bi-partite apicoplast targeting sequence similar to that demonstrated on the PfPREX polypeptide, capable of delivering marker proteins to the apicoplast. Unlike the P. falciparum gene that is devoid of introns, the T. gondii prex gene carries 19 introns, which are spliced to produce a contiguous mRNA. Bacterial expression of the polymerase domain reveals the protein to be active. Consistent with the reported absence of a plastid in Cryptosporidium species, in silico analysis of their genomes failed to demonstrate an orthologue of prex. These studies indicate that prex is conserved across the plastid-bearing apicomplexans and may play an important role in the replication of the plastid genome.",
keywords = "animals, DNA helicases, DNA primase, DNA replication, DNA, protozoan, DNA-directed DNA polymerase, exons, genome, protozoan, introns, mice, mice, inbred BALB C, molecular sequence data, multienzyme eomplexes, plastids, protozoan proteins, sequence analysis, DNA, toxoplasma",
author = "A Mukhopadhyay and C-Y Chen and C Doerig and Henriquez, {F L} and Roberts, {C W} and Barrett, {M P} and Craig Roberts",
year = "2009",
month = "6",
doi = "10.1017/S0031182009006027",
language = "English",
volume = "136",
pages = "747--755",
journal = "Parasitology",
issn = "0031-1820",
number = "7",

}

Mukhopadhyay, A, Chen, C-Y, Doerig, C, Henriquez, FL, Roberts, CW, Barrett, MP & Roberts, C 2009, 'The Toxoplasma gondii plastid replication and repair enzyme complex, PREX' Parasitology, vol. 136, no. 7, pp. 747-755. https://doi.org/10.1017/S0031182009006027

The Toxoplasma gondii plastid replication and repair enzyme complex, PREX. / Mukhopadhyay, A; Chen, C-Y; Doerig, C; Henriquez, F L; Roberts, C W; Barrett, M P; Roberts, Craig.

In: Parasitology, Vol. 136, No. 7, 06.2009, p. 747-755.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The Toxoplasma gondii plastid replication and repair enzyme complex, PREX

AU - Mukhopadhyay, A

AU - Chen, C-Y

AU - Doerig, C

AU - Henriquez, F L

AU - Roberts, C W

AU - Barrett, M P

AU - Roberts, Craig

PY - 2009/6

Y1 - 2009/6

N2 - A plastid-like organelle, the apicoplast, is essential to the majority of medically and veterinary important apicomplexan protozoa including Toxoplasma gondii and Plasmodium. The apicoplast contains multiple copies of a 35 kb genome, the replication of which is dependent upon nuclear-encoded proteins that are imported into the organelle. In P. falciparum an unusual multi-functional gene, pfprex, was previously identified and inferred to encode a protein with DNA primase, DNA helicase and DNA polymerase activities. Herein, we report the presence of a prex orthologue in T. gondii. The protein is predicted to have a bi-partite apicoplast targeting sequence similar to that demonstrated on the PfPREX polypeptide, capable of delivering marker proteins to the apicoplast. Unlike the P. falciparum gene that is devoid of introns, the T. gondii prex gene carries 19 introns, which are spliced to produce a contiguous mRNA. Bacterial expression of the polymerase domain reveals the protein to be active. Consistent with the reported absence of a plastid in Cryptosporidium species, in silico analysis of their genomes failed to demonstrate an orthologue of prex. These studies indicate that prex is conserved across the plastid-bearing apicomplexans and may play an important role in the replication of the plastid genome.

AB - A plastid-like organelle, the apicoplast, is essential to the majority of medically and veterinary important apicomplexan protozoa including Toxoplasma gondii and Plasmodium. The apicoplast contains multiple copies of a 35 kb genome, the replication of which is dependent upon nuclear-encoded proteins that are imported into the organelle. In P. falciparum an unusual multi-functional gene, pfprex, was previously identified and inferred to encode a protein with DNA primase, DNA helicase and DNA polymerase activities. Herein, we report the presence of a prex orthologue in T. gondii. The protein is predicted to have a bi-partite apicoplast targeting sequence similar to that demonstrated on the PfPREX polypeptide, capable of delivering marker proteins to the apicoplast. Unlike the P. falciparum gene that is devoid of introns, the T. gondii prex gene carries 19 introns, which are spliced to produce a contiguous mRNA. Bacterial expression of the polymerase domain reveals the protein to be active. Consistent with the reported absence of a plastid in Cryptosporidium species, in silico analysis of their genomes failed to demonstrate an orthologue of prex. These studies indicate that prex is conserved across the plastid-bearing apicomplexans and may play an important role in the replication of the plastid genome.

KW - animals

KW - DNA helicases

KW - DNA primase

KW - DNA replication

KW - DNA, protozoan

KW - DNA-directed DNA polymerase

KW - exons

KW - genome, protozoan

KW - introns

KW - mice

KW - mice, inbred BALB C

KW - molecular sequence data

KW - multienzyme eomplexes

KW - plastids

KW - protozoan proteins

KW - sequence analysis, DNA

KW - toxoplasma

UR - http://dx.doi.org/10.1017/S0031182009006027

U2 - 10.1017/S0031182009006027

DO - 10.1017/S0031182009006027

M3 - Article

VL - 136

SP - 747

EP - 755

JO - Parasitology

T2 - Parasitology

JF - Parasitology

SN - 0031-1820

IS - 7

ER -

Mukhopadhyay A, Chen C-Y, Doerig C, Henriquez FL, Roberts CW, Barrett MP et al. The Toxoplasma gondii plastid replication and repair enzyme complex, PREX. Parasitology. 2009 Jun;136(7):747-755. https://doi.org/10.1017/S0031182009006027