RRC ID 28144
Author Diray-Arce J, Liu B, Cupp JD, Hunt T, Nielsen BL.
Title The Arabidopsis At1g30680 gene encodes a homologue to the phage T7 gp4 protein that has both DNA primase and DNA helicase activities.
Journal BMC Plant Biol.
Abstract BACKGROUND:The Arabidopsis thaliana genome encodes a homologue of the full-length bacteriophage T7 gp4 protein, which is also homologous to the eukaryotic Twinkle protein. While the phage protein has both DNA primase and DNA helicase activities, in animal cells Twinkle is localized to mitochondria and has only DNA helicase activity due to sequence changes in the DNA primase domain. However, Arabidopsis and other plant Twinkle homologues retain sequence homology for both functional domains of the phage protein. The Arabidopsis Twinkle homologue has been shown by others to be dual targeted to mitochondria and chloroplasts.
RESULTS:To determine the functional activity of the Arabidopsis protein we obtained the gene for the full-length Arabidopsis protein and expressed it in bacteria. The purified protein was shown to have both DNA primase and DNA helicase activities. Western blot and qRT-PCR analysis indicated that the Arabidopsis gene is expressed most abundantly in young leaves and shoot apex tissue, as expected if this protein plays a role in organelle DNA replication. This expression is closely correlated with the expression of organelle-localized DNA polymerase in the same tissues. Homologues from other plant species show close similarity by phylogenetic analysis.
CONCLUSIONS:The results presented here indicate that the Arabidopsis phage T7 gp4/Twinkle homologue has both DNA primase and DNA helicase activities and may provide these functions for organelle DNA replication.
Volume 13
Pages 36
Published 2013-3-4
DOI 10.1186/1471-2229-13-36
PII 1471-2229-13-36
PMID 23452619
PMC PMC3610141
MeSH Arabidopsis / enzymology* Arabidopsis / genetics Bacteriophage T7 / enzymology* DNA Helicases / genetics DNA Helicases / metabolism* DNA Primase / genetics DNA Primase / metabolism* Viral Envelope Proteins / genetics Viral Envelope Proteins / metabolism*
IF 3.93
Times Cited 14
Arabidopsis / Cultured plant cells, genes pda12351