+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Guanylyltransferase activity of the LEF-4 subunit of baculovirus RNA polymerase



Guanylyltransferase activity of the LEF-4 subunit of baculovirus RNA polymerase



Journal of Virology 72(12): 10003-10010



The baculovirus Autographa californica nuclear polyhedrosis virus encodes a DNA-dependent RNA polymerase that transcribes viral late genes. This polymerase is composed of four equimolar subunits, LEF-4, LEF-8, LEF-9, and p47. Here we present data indicating that the LEF-4 subunit of RNA polymerase is a guanylyltransferase. Incubation of RNA polymerase in the presence of divalent cation and radiolabeled GTP resulted in the formation of a covalent enzyme-guanylate complex that comigrated with the LEF-4 subunit. The label transfer assay showed an absolute requirement for divalent cation which could be satisfied by either manganese or magnesium. The reaction was specific for guanine nucleotides, and GTP was more effective than dGTP in the formation of enzyme-guanylate complex. To demonstrate that LEF-4 was the guanylyltransferase, the single subunit was overexpressed in baculovirus-infected cells. The overexpressed protein was primarily cytosolic, indicating that other proteins in the RNA polymerase complex were responsible for nuclear targeting of LEF-4. LEF-4 alone was able to covalently bind GMP, although less efficiently than viral RNA polymerase.

Please choose payment method:






(PDF emailed within 1 workday: $29.90)

Accession: 003157235

Download citation: RISBibTeXText

PMID: 9811738


Related references

Recombinant-baculovirus-expressed PB-2 subunit of the influenza A virus RNA polymerase binds cap groups as an isolated subunit. Virus Research 42(1-2): 1-9, 1996

The polymerase subunit of dna polymerase iii of escherichia coli 1. amplification of the dnae gene product and polymerase activity of the alpha subunit. Journal of Biological Chemistry 260(24): 12982-12986, 1985

Baculovirus P35 interacts with a subunit of human RNA polymerase II and can enhance promoter activity in human cells. Journal of General Virology 84(Pt 11): 3011-3019, 2003

The polymerase subunit of DNA polymerase III of Escherichia coli. Amplification of the dnaE gene product and polymerase activity of the a subunit. The Journal of Biological Chemistry 260: 982-6, 1985

The LEF-4 subunit of baculovirus RNA polymerase has RNA 5'-triphosphatase and ATPase activities. Journal of Virology 72(12): 10011-9, 1998

Functional characterization of the largest subunit of a Baculovirus RNA polymerase. Abstracts of the General Meeting of the American Society for Microbiology 102: 469, 2002

Characterization of the human DNA polymerase delta catalytic subunit expressed by a recombinant baculovirus. NagoyaJournalofMedicalScience63(3-4):99, 2000

Baculovirus expression of the 11 mycoreovirus-1 genome segments and identification of the guanylyltransferase-encoding segment. Journal of General Virology 88(Pt 1): 342-350, 2007

Baculovirus expression of the 11 mycoreovirus-1 genome segments and identification of the guanylyltransferase-encoding segment. Journal of General Virology 88(Part 1): 342-350, 2007

Purification and characterization of the catalytic subunit of human DNA polymerase d expressed in baculovirus-infected insect cells. The Journal of Biological Chemistry 271: 740-5, 1996

Catalytic subunit of human DNA polymerase a overproduced from baculovirus-infected insect cells. Structural and enzymological characterization. The Journal of Biological Chemistry 266: 739-48, 1991

Purification and characterization of the catalytic subunit of human DNA polymerase delta expressed in baculovirus-infected insect cells. Journal of Biological Chemistry 271(47): 29740-5, 1996