Abstract
30S ribosomal protein S4 contains a single cysteine residue at position 31. We have selectively cleaved the peptide bond adjacent to this residue using the reagent 2-nitro-5-thiocyano-benzoic acid. The two resultant fragments were purified. The smaller S4-fragment (1-30) was found to be incapable of interacting with 16S RNA directly. This fragment also is not incorporated into a particle reconstituted from 16S RNA and 20 purified proteins with S4 missing. In contrast, the large S4- fragment (31-203) appears to be fully functional in ribosome assembly. Replacement of S4 with this fragment in the reconstitution reaction leads to a complete 30S ribosome containing all 30S proteins. This particle has a full capacity to bind poly U but has lost all activity for poiy U directed phe-tRNA binding. We therefore propose that the N-terminus of protein S4 is not critical for ribosome assembly but is essential for tRNA binding.
Original language | English (US) |
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Pages (from-to) | 2789-2800 |
Number of pages | 12 |
Journal | Nucleic acids research |
Volume | 5 |
Issue number | 8 |
DOIs | |
State | Published - Aug 1978 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Genetics