Expression of the gene for ribosomal protein S20: effects of gene dosage.

AUTOR(ES)

Parsons, G D

RESUMO

We have exploited the properties of three different plasmids which carry the gene for Escherichia coli ribosomal protein S20 (rpsT) to test the effects of gene dosage on the expression of rpsT. Over a range of total copies of rpsT of 1 to 58 per haploid genome equivalent, the rate of incorporation of uridine during a 30-s pulse into RNA annealing to either of two specific probes for S20 mRNA increased essentially in proportion to copy number. In contrast, the rate of synthesis of S20 protein increased no more than 2.1-fold at the highest copy number. We conclude, in contrast to an earlier report (D. Geyl, and A. Böck, Mol. Gen. Genet. 154:327-334, 1977), that the synthesis of S20 is regulated at a posttranscriptional step. We propose that S20 itself is the regulatory agent and that binding of S20 to its own mRNA in regions homologous in structure with 16S rRNA can account for our results.

Documentos Relacionados

• Expression of ribosomal protein genes cloned in a hybrid plasmid in Escherichia coli: gene dosage effects on synthesis of ribosomal proteins and ribosomal protein messenger ribonucleic acid.
• Posttranscriptional regulation of ribosomal protein S20 and stability of the S20 mRNA species.
• Wide variability in the sensitivity of APTT reagents for monitoring of heparin dosage.
• Nucleotide sequence of the Euglena gracilis chloroplast gene for ribosomal protein L20.
• Affinities of ribosomal protein S20 and C-terminal deletion mutants for 16S rRNA and S20 mRNA.