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Biomedical subjects

M Schweiger

Publications and source records attributed to M Schweiger.

At least 199 records · Page 11Linked to original sources
PubMed1975

Transcriptional units for ribosomal proteins of Escherichia coli.

Transcriptional units for ribosomal proteins in Escherichia coli were measured using the ultraviolet sensitivities of the rates of synthesis of individual ribosomal proteins. The ultraviolet sensitivities of gene transcriptions are proportional to the distances from the promoters. The longest transcriptional units for ribosomal proteins are 3.6 x 10(6) of DNA molecular weight corresponding to 1.8 x 10(6) of RNA or to 180 000 of protein. The length would cover 10--12 genes of ribosomal proteins (of an average Mr of 15000-18000).

Bacterial Proteins↗
PubMed1975

In vivo and in vitro phosphorylation of DNA-dependent RNA polymerase of Escherichia coli by bacteriophage-T7-induced protein kinase.

After infection with bacteriophage T7 the beta' and to a lesser extent the beta subunits of E. coli DNA-dependent RNA polymerase (nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6) are phosphorylated by a phage-gene-encoded protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37). The phosphorylation occurs on threonine residues and appears site-specific. It is probably the molecular basis of the early transcriptional control.

Coliphages↗
PubMed1974

Protein kinase induction in Escherichia coli by bacteriophage T7.

After bacteriophage T7 infection, a protein kinase (EC 2.7.1.37; ATP:protein phosphotransferase) activity can be demonstrated in E. coli in vivo by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Cell-free extracts catalyzed the transfer of the terminal phosphoryl group of [(gamma)-(32)P]ATP to endogenous protein acceptor or to added histone. The bond between phosphate and protein shows the characteristics of serine phosphate: it is stable in 1 N HCl (100 degrees ) and cleaved by 1 N KOH (37 degrees ) and by alkaline phosphatase treatment. Moreover, after partial acid hydrolysis, radiophosphate migrates with marker O-phosphoserine on polyethyleneimine-cellulose thin-layer chromatograms. Enzyme activity in uninfected cells is negligible. Ultraviolet irradiation of the phage genome prevents the appearance of the protein kinase; irradiation of the host genome does not. The enzyme activity occurs 4 min after infection and its gene maps in the early region (promoter proximal to gene 1). Ribosomal proteins are phosphorylated in vivo and are substrates in vitro. Enzyme activity in vitro is not changed by addition of cyclic AMP or cyclic GMP.

Adenosine Triphosphate↗
PubMed1972

Negative control of protein synthesis after infection with bacteriophage T7.

T7 phage induces two negative control mechanisms of protein synthesis: (a) Host-gene expression is repressed by a "T7 repressor," and (b) early T7 protein synthesis is inhibited by a late phage protein.(a) The repressor for host enzyme synthesis is an early T7 protein. Its gene is none of the known early genes; it is located promotor-proximal to gene 1. The repressor function of this protein can be demonstrated by DNA-dependent enzyme synthesis in vitro.(b) Expression of early phage gene is depressed by a late phage protein or by T7 RNA polymerase. Control takes place on the level of transcription.

Bacterial Proteins↗