Properties of avian sarcoma-leukosis virus pp32-related pol-endonucleases produced in Escherichia coli

R. Terry, D. A. Soltis, M. Katzman, D. Cobrinik, J. Leis, A. M. Skalka

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


The gag-pol precursor protein of the avian sarcoma-leukosis virus is processed into three known pol-encoded mature polypeptides; the 95- and 63-kilodalton (kDa) β and α subunits, respectively, of reverse transcriptase and the 32-kDa pp32 protein. The pp32 protein possesses DNA endonuclease activity and is produced from the precursor by two proteolytic cleavage events, one of which removes 4.1 kDa of protein from the C terminus.A 36-kDa protein (p36(pol)) which retains this C-terminal segment is detectable in small quantities in virions. We have constructed Escherichia coli plasmid clones that express the C-terminal domains of pol corresponding to pp32 and p36. These proteins have been purified by column chromatographic methods to near homogeneity. No significant differences could be detected in the enzymatic properties of the bacterially produced p32(pol) and p36(pol) proteins. Both possess DNA endonuclease activity and, like the pp32 protein isolated from virions, can cleave near the junction of two tandem avian sarcoma-leukosis virus long terminal repeats in double-stranded supercoiled DNA substrates. In the presence of Mg2+, both p32(pol) and viral pp32 cleave either strand of DNA 2 nucleotides 5' to the junction.

Original languageEnglish (US)
Pages (from-to)2358-2365
Number of pages8
JournalJournal of virology
Issue number7
StatePublished - 1988

All Science Journal Classification (ASJC) codes

  • Microbiology
  • Immunology
  • Insect Science
  • Virology


Dive into the research topics of 'Properties of avian sarcoma-leukosis virus pp32-related pol-endonucleases produced in Escherichia coli'. Together they form a unique fingerprint.

Cite this