Location of the structural gene for fructose-1,6-diphosphate aldolase in Escherichia coli

Molecular cloning, nucleotide sequence and fine-structural analysis of the Corynebacterium glutamicum fda gene: structural comparison of C. glutamicum fructose-1,6-biphosphate aldolase to class I and class II aldolases

The Corynebacterium glutamicum fda gene encoding fructose-1,6-biphosphate (FBP) aldolase has been isolated by complementation of an Escherichia coli mutant. The nucleotide sequence of a 3371 bp chromosomal fragment containing the C. glutamicum fda gene was determined. The N-terminal amino acid sequence of C. glutamicum FBP aldolase identified the correct initiation site for the fda gene, and a molecular weight of 37,092 was predicted for the fda polypeptide. S1 nuclease mapping identified the transcriptional start site, and Northern hybridization analysis indicated that the fda gene encodes a single 1.3 kb transcript. The primary structure of C. glutamicum FBP aldolase shows strong homology to class II FBP aldolases. Conservation of primary structure was observed between class I and class II aldolases, but several residues essential for catalytic activity in class I aldolases were absent from class II aldolases.

ColE1 hybrid plasmids for Escherichia coli genes of glycolysis and the hexose monophosphate shunt

The Clarke-Carbon clone bank carrying ColE1-Escherichia coli DNA has been screened by conjugation for complementation of glycolysis and hexose monophosphate shunt mutations. Plasmids were identified for phosphofructokinase (pfkA), triose phosphate isomerase (tpi), phosphoglucose isomerase (pgi), glucose-6-phosphate dehydrogenase (zwf), gluconate-6-phosphate dehydrogenase (gnd), enolase (eno), phosphoglycerate kinase (pgk), and fructose-1,6-P2 aldolase (fda). Enzyme levels for the plasmid-carried gene ranged, for the various plasmids, from 4- to 25-fold the normal level.

Two major groups of colicin factors: their molecular weights

Colicin factors are thought to fall into two taxonomic groups which differ in, amongst other properties, the molecular weight of the plasmid DNA and the host range of the colicin protein. This hypothesis is supported by the plasmids found in 26 colicinogenic strains. Two small Col factors may have arisen from larger factors, judging from similarities between their colicins.

Glyceraldehyde 3-p dehydrogenase, glycerate 3-P kinase and enolase mutants of Escherichia coli: genetic studies

The genetic loci for two enzymes of glycolysis have been established by transductional crosses. The eno locus, likely to be the structural gene for enolase maps in the 52-minute region of the Escherichia coli chromosome. A structural determinant for glycerate 3-P kinase (pgk) is located near serA. The map order is speB-pgk-serA-lysA-argA-eno-cysC. In the 35-minute region maps a locus affecting the structure of glyceraldehyde 3-P dehydrogenase.

Rapid cessation of phospholipid synthesis in fructose-1,6-diphosphate aldolase mutants of Escherichia coli

Escherichia coli GH352, which was originally described as a temperature-sensitive strain containing a thermolabile acyl coenzyme A:monoacylglycerol 3-phosphate acyltransferase, does not now contain a thermolabile form of this enzyme. It has a defect in fructose-1,6-diphosphate aldolase and at least one additional temperature-sensitive lesion. Both strains GH352 and NP315, a temperature-sensitive aldolase mutant, show rapid cessation of 32-P1 incorporation into nucleic acids and phospholipids at 42 C. These characteristics of strain GH352 are therefore no longer attributed to thermolabile phospholipid synthesis, but can be attributed to the fructose-1,6-diphophate aldolase lesion.