TY - JOUR

T1 - Nucleotide sequence of the Escherichia coli pyrE gene and of the DNA in front of the protein-coding region

AU - Poulsen, Peter

AU - Jensen, Kaj Frank

AU - Valentin-Hansen, Poul

AU - Carlsson, Peter

AU - Lundberg, Lennart G.

PY - 1983

Y1 - 1983

N2 - Orotate phosphoribosyltransferase (EC 2.4.2.10) was purified to electrophoretic homogeneity from a strain of Escherichia coli containing the pyrE gene cloned on a multicopy plasmid. The relative molecular masses (Mr) of the native enzyme and its subunit were estimated by means of gel filtration and electrophoresis in the presence of dodecyl sulfate. The amino acid sequences at the N and C termini, as well as the amino acid composition, were determined. The nucleotide sequence of the structural pyrE gene, including 394 nucleotide residues preceding the beginning of the coding frame, was also established. From the results the following conclusions may be drawn. Orotate phosphoribosyltransferase is a dimeric protein with subunits of Mr 23 326 consisting of 211 amino acid residues. The pyrE gene is transcribed in a counter-clockwise direction from the E. coli chromosome as an mRNA with a considerable leader segment in front of the protein-coding region. This leader contains a structure with features characteristic for a (translated?) rho-independent transcriptional terminator, which is preceded by a cluster of uridylate residues. This indicates that the frequency of pyrE transcription is regulated by an RNA polymerase (UTP) modulated attenuation.

AB - Orotate phosphoribosyltransferase (EC 2.4.2.10) was purified to electrophoretic homogeneity from a strain of Escherichia coli containing the pyrE gene cloned on a multicopy plasmid. The relative molecular masses (Mr) of the native enzyme and its subunit were estimated by means of gel filtration and electrophoresis in the presence of dodecyl sulfate. The amino acid sequences at the N and C termini, as well as the amino acid composition, were determined. The nucleotide sequence of the structural pyrE gene, including 394 nucleotide residues preceding the beginning of the coding frame, was also established. From the results the following conclusions may be drawn. Orotate phosphoribosyltransferase is a dimeric protein with subunits of Mr 23 326 consisting of 211 amino acid residues. The pyrE gene is transcribed in a counter-clockwise direction from the E. coli chromosome as an mRNA with a considerable leader segment in front of the protein-coding region. This leader contains a structure with features characteristic for a (translated?) rho-independent transcriptional terminator, which is preceded by a cluster of uridylate residues. This indicates that the frequency of pyrE transcription is regulated by an RNA polymerase (UTP) modulated attenuation.

U2 - 10.1111/j.1432-1033.1983.tb07641.x

DO - 10.1111/j.1432-1033.1983.tb07641.x

M3 - Journal article

VL - 135

SP - 223

EP - 229

JO - F E B S Journal

JF - F E B S Journal

SN - 1742-464X

IS - 2

ER -