Cloning and characterization of the Escherichia coli phosphoglycerate kinase (pgk) gene.
The pgk gene of Escherichia coli coding for the phosphoglycerate kinase was subcloned from the Carbon and Clarke collection plasmid pLC33-5. The position and direction of transcription of the pgk gene was determined by Tn5 insertion mutagenesis. Analysis of proteins encoded from these plasmids showed that the pgk gene product is a 40-kDa protein, and that the gene is transcribed from two promoters, one immediately in front of the gene and one in front of an upstream gene coding for a 38-kDa polypeptide of unknown function. The position of the Pgk protein on two-dimensional O'Farrel gels was identified, and from this we conclude that it is one of the proteins induced by anaerobiosis [Smith and Neidhardt, J. Bacteriol. 154 (1987) 336-343]. The pgk gene was also found to show growth phase regulation; the synthesis of Pgk protein was induced more than ten-fold during transition from the exponential to the stationary growth phase.