Removal of beta subunit of the eukaryotic polypeptide chain initiation factor 2 by limited proteolysis.
- 1 July 1981
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 78 (7) , 4128-4132
- https://doi.org/10.1073/pnas.78.7.4128
Abstract
It is generally considered that the eukaryotic polypeptide chain initiation factor 2 (eIF-2) from rabbit reticulocytes consists of three nonidentical subunits termed alpha, beta, and gamma, in order of increasing molecular weight. However, a recent report [Stringer, E. A., Chaudhuri, A., Valenzuela, D. & Maitra, U. (1980) Proc. Natl. Acad. Sci. USA 77, 3356-3359] suggested that this factor is made up of only two subunits. In this paper we show that limited proteolysis of rabbit reticulocyte eIF-2 leads to loss of the beta subunit. This modified eIF-2 has the same activity as the native factor in promoting ternary (eIF-2.GTP.Met-tRNAi) and 40S (eIF-2.GTP.Met-tRNAi.40S ribosome) initiation complex formation. Like native eIF-2, the protease-treated factor can restore translation in heme-deficient lysates. On the other hand, the treated factor is less stable than the native protein.This publication has 23 references indexed in Scilit:
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