Identification and initial characterization of translational initiation factor 2 from bovine mitochondria.

Journal Article (Journal Article)

The bovine liver mitochondrial factor that promotes the binding of fMet-tRNA to mitochondrial ribosomes, initiation factor 2 (IF-2mt), has been identified in the postribosomal supernatant fraction of isolated liver mitochondria. This factor has been purified approximately 5,000-fold and present preparations are estimated to be about 10% pure. IF-2mt has an apparent molecular weight of about 140,000 as determined by gel filtration chromatography. IF-2mt is active in stimulating fMet-tRNA binding to Escherichia coli ribosomes but E. coli IF-2 is not active in promoting initiator tRNA binding to animal mitochondrial ribosomes. The IF-2mt-mediated binding of fMet-tRNAi(Met) to mitochondrial ribosomes is dependent on the presence of a message such as poly(A,U,G) and on GTP. Nonhydrolyzable analogs of GTP are 2-3-fold less effective in promoting initiation complex formation on mitochondrial ribosomes than is GTP suggesting that IF-2mt is capable of recycling to some extent under the current assay conditions.

Full Text

Duke Authors

Cited Authors

  • Liao, HX; Spremulli, LL

Published Date

  • August 15, 1990

Published In

Volume / Issue

  • 265 / 23

Start / End Page

  • 13618 - 13622

PubMed ID

  • 2380177

International Standard Serial Number (ISSN)

  • 0021-9258


  • eng

Conference Location

  • United States