Characterization of three genes in the dam-containing operon of Escherichia coli

TY - JOUR

T1 - Characterization of three genes in the dam-containing operon of Escherichia coli

AU - Lyngstadaas, A

AU - Løbner-Olesen, A

AU - Boye, E

PY - 1995/6/10

Y1 - 1995/6/10

N2 - The dam-containing operon in Escherichia coli is located at 74 min on the chromosomal map and contains the genes aroK, aroB, a gene called urf74.3, dam and trpS. We have determined the nucleotide sequence between the dam and trpS genes and show that it encodes two proteins with molecular weights of 24 and 27 kDa. Furthermore, we characterize the three genes urf74.3, 24kDa, 27kDa and the proteins they encode. The predicted amino acid sequences of the 24 and 27 kDa proteins are similar to those of the CbbE and CbbZ proteins, respectively, of the Alcaligenes eutrophus cbb operon, which encodes enzymes involved in the Calvin cycle. In separate experiments, we have shown that the 24 kDa protein has d-ribulose-5-phosphate epimerase activity (similar to CbbE), and we call the gene rpe. Similarly, the 27 kDa protein has 2-phosphoglycolate phosphatase activity (similar to CbbZ), and we name the gene gph. The Urf74.3 protein, with a predicted molecular weight of 46 kDa, migrated as a 70 kDa product under denaturing conditions. Overexpression of Urf74.3 induced cell filamentation, indicating that Urf74.3 directly or indirectly interferes with cell division. We present evidence for translational coupling between aroB and urf74.3 and also between rpe and gph. Proteins encoded in the dam superoperon appear to be largely unrelated: Dam, and perhaps Urf74.3, are involved in cell cycle regulation, AroK, AroB, and TrpS function in aromatic amino acid biosynthesis, whereas Rpe and Gph are involved in carbohydrate metabolism.

AB - The dam-containing operon in Escherichia coli is located at 74 min on the chromosomal map and contains the genes aroK, aroB, a gene called urf74.3, dam and trpS. We have determined the nucleotide sequence between the dam and trpS genes and show that it encodes two proteins with molecular weights of 24 and 27 kDa. Furthermore, we characterize the three genes urf74.3, 24kDa, 27kDa and the proteins they encode. The predicted amino acid sequences of the 24 and 27 kDa proteins are similar to those of the CbbE and CbbZ proteins, respectively, of the Alcaligenes eutrophus cbb operon, which encodes enzymes involved in the Calvin cycle. In separate experiments, we have shown that the 24 kDa protein has d-ribulose-5-phosphate epimerase activity (similar to CbbE), and we call the gene rpe. Similarly, the 27 kDa protein has 2-phosphoglycolate phosphatase activity (similar to CbbZ), and we name the gene gph. The Urf74.3 protein, with a predicted molecular weight of 46 kDa, migrated as a 70 kDa product under denaturing conditions. Overexpression of Urf74.3 induced cell filamentation, indicating that Urf74.3 directly or indirectly interferes with cell division. We present evidence for translational coupling between aroB and urf74.3 and also between rpe and gph. Proteins encoded in the dam superoperon appear to be largely unrelated: Dam, and perhaps Urf74.3, are involved in cell cycle regulation, AroK, AroB, and TrpS function in aromatic amino acid biosynthesis, whereas Rpe and Gph are involved in carbohydrate metabolism.

KW - Amino Acid Sequence

KW - Bacterial Proteins/biosynthesis

KW - Base Sequence

KW - Chromosome Mapping

KW - Escherichia coli/enzymology

KW - Escherichia coli Proteins

KW - Genes, Bacterial/genetics

KW - Methyltransferases/genetics

KW - Molecular Sequence Data

KW - Mutagenesis, Insertional

KW - Operon/genetics

KW - Site-Specific DNA-Methyltransferase (Adenine-Specific)

M3 - Journal article

C2 - 7603433

SN - 0026-8925

VL - 247

SP - 546

EP - 554

JO - Molecular General Genetics

JF - Molecular General Genetics

IS - 5

ER -