THE GENE ENCODING THE ELONGATION-FACTOR-P PROTEIN IS ESSENTIAL FOR VIABILITY AND IS REQUIRED FOR PROTEIN-SYNTHESIS

Citation
H. Aoki et al., THE GENE ENCODING THE ELONGATION-FACTOR-P PROTEIN IS ESSENTIAL FOR VIABILITY AND IS REQUIRED FOR PROTEIN-SYNTHESIS, The Journal of biological chemistry, 272(51), 1997, pp. 32254-32259
Citations number
41
ISSN journal
00219258
Volume
272
Issue
51
Year of publication
1997
Pages
32254 - 32259
Database
ISI
SICI code
0021-9258(1997)272:51<32254:TGETEP>2.0.ZU;2-N
Abstract
Elongation factor P (EFP) is a protein that stimulates the peptidyltra nsferase activity of fully assembled 70 S prokaryotic ribosomes and en hances the synthesis of certain dipeptides initiated by N-formylmethio nine. This reaction appears conserved throughout species and is promot ed in eukaryotic cells by a homologous protein, eIF5A. Here we ask whe ther the Escherichia coil gene encoding EFP is essential for cell viab ility, A kanamycin resistance (Kan(R)) gene was inserted near the N-te rminal end of the efp gene and was cloned into a plasmid, pMAK705, tha t has a temperature-sensitive origin of replication. After transformat ion into a recA(+) E. coli strain, temperature-sensitive mutants were isolated, and their chromosomal DNA was sequenced. Mutants containing the efp-Kan(R) gene in the chromosome grew at 33 degrees C only in the presence of the wild-type copy of the efp gene in the pMAK705 plasmid and were unable to grow at 44 degrees C. Incorporation of various iso topes in vivo suggests that translation is impaired in the efp mutant at 44 degrees C. At 44 degrees C, mutant cells are severely defective in peptide-bond formation. We conclude that the efp gene is essential for cell viability and is required for protein synthesis.