Analysis of the relA gene product of Escherichia coli.

Abstract

The relA gene product, ATP: GTP 3'-pyrophosphotransferase (stringent factor) has been isolated in homogeneous form from an Escherichia coli strain polyploid for this gene at a yield of 1 mg/100 g cells and at a specific activity in a ribosome-activated assay at 37 degrees C of 120 mumol guanosine pentaphosphate formed min-1 mg protein-1. The specific activity in a methanol-activated assay at 25 degrees C was found to be 4 mumol guanosine pentaphosphate formed min-1 mg protein-1. These values are about 100 times higher than reported by others. Our further studies of this enzyme led to the following results. Antibodies raised against this enzyme inhibit the ribosome-activated synthesis of guanosine tetraphosphate and pentaphosphate but have no effect on the much slower synthesis, detected in the absence of ribosomes. The amount of stringent factor in the relA+ strain CP78 is estimated to about 1 copy per 200 ribosomes. The amount of antibody-binding material in CP79 (relA) is at least 5 times lower.

• Authors: F S Pedersen, N O Kjeldgaard
• Journal: European journal of biochemistry (Eur J Biochem) Vol. 76 Issue 1 Pg. 91-7 (Jun 01 1977) ISSN: 0014-2956 [Print] England
• PMID: 195816 (Publication Type: Journal Article)

Chemical References

• Antibodies, Bacterial
• Guanine Nucleotides
• Phosphoric Acids
• Ribosomal Proteins
• Guanosine Triphosphate
• Phosphotransferases

Topics

• Antibodies, Bacterial
• Antibody Formation
• Binding Sites, Antibody
• Drug Stability
• Escherichia coli (enzymology)
• Genes
• Guanine Nucleotides (metabolism)
• Guanosine Triphosphate (metabolism)
• Phosphoric Acids
• Phosphotransferases (isolation & purification, metabolism)
• Polyploidy
• Precipitin Tests
• Ribosomal Proteins (isolation & purification)
• Species Specificity