Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In DNA preparations isolated from regenerating rat liver 22 hours after partial hepatectomy, i.e. at the period of the most intensive DNA synthesis a "Denaturating Protein Factor" (DPF) tightly bound to DNA was found. Isolated protein fraction with a molecular weight of 6500 dalton was found to be homogenous upon SDS-polyacrylamide electrophoresis. The degree of destabilisation of DNA was estimated by its reaction with water-soluble [14C]CME-carbodiimide which modifies selectively guanine and thymine residues only in the denatured DNA regions. Pronase treated DPF loses its DNA-denaturing capacity. Pronase treatment of DNA--DPF complex restores native DNA structure. DPF from rat liver was able to denature DNA from calf thymus and bacteriophage T7 DNA. A hypothesis is proposed that the DPF is responsible for the destabilization of DNA secondary structure in the process of replication.
Mol Biol (Mosk)
PMID:[Protein factor from regenerating rat liver destabilizing secondary DNA structure]. 75 92

We describe a bacterial RNA polymerase mutation, rif 501, which confers rifampicin resistance and thermosensitivity to E. coli K 12. The purified RNA polymerase enzyme from rif 501 bacteria shows increased heatsensitivity in vitro at 51 degrees C. However, in vivo, at 42 degrees C the non-permissive temperature, mutant bacteria continue to grow and to synthesize RNA for 90 min. On a lawn of the mutant bacteria, at 40-41 degrees C, phage lambda forms clear plaques (LycA phenotype); this is probably due to an enhancement of cro function; we surmise that at 42 degrees C the transcription originating from the pR (but not from the pL) promoter on the lamdba genome becomes N-independent and less sensitive to the absence of the cro product. We discuss the possibility that both the N and cro proteins of phage lambda interact directly with the bacterial RNA polymerase. These observations indicate that the loss of viability of the rif 501 mutant at the restrictive temperature is not a consequence of an immediate inactivation of RNA polymerase; rather we feel it is due to a modification of the activity of RNA polymerase, leading to a disruption of the cellular regulation.
Mol Gen Genet 1976 Apr 23
PMID:A bacterial RNA polymerase mutant that renders lambda growth independent of the N and cro functions at 42 degrees C. 77 9

The phenomenon of glucose catabolite repression was studied in E. coli mutants inable to transport this carbohydrate. The pts 1, H mutant P34 was much less sensitive to the repressive effect of glucose on beta-galactosidase synthesis than the parent type. The 1103 mutant devoid of enzyme 1 of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) behaves in the same way as P34 mutant after addition of glucose to casamino acid mineral medium. However, in minimal medium with succinate as the sole source of carbon, cells of the 1103 mutant show enhanced sensibility to transient glucose repression. The effect of hypersensibility disappears when the lac I mutation leading to constitutive the beta-galactosidase synthesis is introduced in 1103 mutant. It is shown that the enhanced sensibility of beta-galactosidase synthesis to glucose transient repression in 1103 mutant is an effect of the aburpt decrease in its growth rate in the presence of succinate and most probably this decrease leads to "inducer exclusion" of the lac operon. It is also shown that if one introduces the P34 mutation in strain JD3 devoid of one of the enzymes II for glucose (and due to this resistant to glucose catabolite respression) then the level of resistance in double mutant does not increase in spite of considerable supression of 14C glucose accumulation. In connection with this the role is discussed of separate components of the E. coli K 12 glucose transport system in realization of the phenomenon of catabolite repression.
Mol Biol (Mosk)
PMID:[Catabolyte repression of Escherichia coli K12 mutants with defects in different systems of glucose transport]. 78 37

After transfer from a mutagenized host, twenty one Co1E2 plasmid mutants were isolated after screening 10,000 clones for abnormal colicin production. Analysis by SDS polyacrylamide slab gel electrophoresis of proteins synthesized after mitomycin C-induction of mutant cultures, indicates that all but two of the mutations are in the structural gene from colicin E2. Of these, nine produce fragments of colicin in both whole cells and minicells and some are suppressed by nonsense suppressors. Studies with a nonsense mutant producing only a small colicin E2 fragment (Co1E2-421) suggest that colicin E2 in not involved in plasmid DNA replication, in the control of its own synthesis, or required for cell death when cells become committed to colicin production. The two plasmid mutants outside the colicin gene segregate plasmid-free cells at 33 degrees, 37 degrees and 43 degrees. One segregates fairly rapidly (about 4% per generation) though the colicin-producing cells make normal amounts of colicin, whilst the other segregates more slowly and the colicin-producing cells make much reduced amounts of colicin.
Mol Gen Genet 1976 Aug 02
PMID:Isolation and characterization of Co1E2 plasmid mutants unable to kill colicin-sensitive cells. 79 89

Chromosomal non-histone proteins are obtained from nuclei of two types of pigeon erythroid cells: erythroblasts (cells active in RNA synthesis) and erythrocytes (cells with repressed RNA synthesis). They are well soluble in solutions of low ionic strength. Electrophoretic separation of the obtained non-histone proteins in polyacrylamide gels with urea and SDS shows the presence of qualitative differences in the pattern of non-histone proteins of chromatine from erythroblasts and erythrocytes. By electrophoresis in urea some protein bands of non-histone proteins of chromatine from erythroblasts were found which disappear with the aging of cells. At the same time two protein fractions were observed in chromatine from erythrocytes which were absent in that of erythroblasts. Disappearance of some high molecular weight protein fractions from erythrocyte chromatine as compared to erythroblasts was observed by separation of the non-histone proteins in the presence of SDS. These fractions of the non-histone proteins disappearing during aging of cells are well extractable from erythroblast chromatine by 0.35 M NaCl solution. In the in vitro system with E. coli RNA polymerase addition of non-histone proteins of chromatine from erythroblasts to chromatine from erythrocytes increases RNA synthesis 2--3 times. At the same time addition of non-histone proteins from erythrocytes is either without any influence on this process or somewhat inhibiting.
Mol Biol (Mosk)
PMID:[Comparative investigation of the non-histone proteins of chromatin from pigeon erythroblasts and erythrocytes]. 80 71

A total of 23 phage specific proteins (including four head and six tail proteins) could be identified after SDS polyacrylamide gel electrophoresis of extracts from phage SPP1 infected Bacillus subtilis cells. The total molecular weight of the proteins amounts to approximately 1.9 X 10(6) daltons, equivalent to the majority of the coding capacity of SPP1 DNA. It can thus be assumed that almost all SPP1 coded proteins have been identified. Protein assignments to phage cistrons were made by analysis of extracts from nonpermissive cells infected with sus-mutants. The SPP1 specified proteins can be subdivided into three groups on the basis of the time of their synthesis during the latent period. Host protein synthesis is not significantly affected by SPP1 infection. Normal expression of host genes appears to be essential for SPP1 growth.
Mol Gen Genet 1975 Dec 23
PMID:Gene expression of bacteriophage SPPI. I. Phage directed protein synthesis. 81 1

A factor reacting with SRBC and rabbit IgG was obtained under mild conditions from rat thymus and spleen. The isolation procedure includes incubation of thymocytes or splenocytes with IgG-cellulose adsorbent, destruction of cells, washing the adsorbent and elution of an adsorbed material at pH 2. This preparation as well as the purified substance previously obtained by affinity chromatography on IgG-cellulose columns were found to agglutinate both SRBC and autologous erythrocytes. Preincubation in 1% SDS leads to dissociation of the preparation into several components separated by gel electrophoresis. A probable relation of this structure to the rosette forming capacity of T-lymphocytes is discussed.
Mol Biol Rep 1977 Mar
PMID:The substance reacting with SRBC (sheep red blood cells) and rabbit IgG. Isolation under mild conditions from rat thymus. 85 1

Heterogeneous nuclear ribonucleoprotein particles (HnRNP) were separated in metrizamide density gradients, into two fractions migrating to 1.31 g ml-1 and 1.18 g ml-1, respectively. Proteins associated with each of these fractions were analysed by SDS-acrylamide gel electrophoresis. It is shown that the whole proteins extracted from these two metrizamide fractions exhibit clearly different electrophoretic patterns: 1.31 HnRNP particles contain as major polypeptide chains molecules with molecular weights ranging from 40,000 to 65,000, while major polypeptides of 1.18 HnRNP are banding in the 30,000-40,000 molecular weight region of the gels. Both fractions contain numerous other associated polypeptide chains whose molecular weights are above 65,000. A possible kinetic relationship between these two HnRNP classes was investigated in vivo by performing chase experiments. No clear evidence for a precursor-product relationship was found. Implications arising from these structural and kinetic observations, and problems relating to nuclear maturation of pre-messenger RNA, are discussed.
Mol Biol Rep 1977 Mar
PMID:A comparative study on the two classes of heterogeneous nuclear ribonucleoprotein particles separated in metrizamide density gradient, by electrophoresis of proteins and chase experiments. Evidence for two distinct subfractions of HnRNP in mammalian nuclei. 87 Aug 20

The isolation of rough and smooth endoplasmic reticulum from rat parotid salivary gland is described. The rough membrane was stripped of its bound ribosomes using the KCl-puromycin method. Rough endoplasmic reticulum was reconstituted from stripped-rough membrane and polyribosomes. The reconstituted rough membrane resembled the native rough membrane in the following aspects: RNA/protein ratio, buoyant density in a continuous sucrose gradient and amino acid incorporation capacity. The in vitro synthesis of alpha-amylase by both rough and in vitro reconstituted rough membrane was demonstrated using SDS polyacrylamide gel electrophoresis. The reconstituted rough membrane could be restripped by KCl-puromycin. The in vitro synthesized alpha-amylase remained associated with the rough or the in vitro reconstituted rough membrane, even after these membranes were stripped of their bound ribosomes.
Mol Biol Rep 1976 Jul
PMID:The synthesis of alpha-amylase by rough and in vitro reconstituted rough endoplasmic reticulum derived from rat parotid gland. 95 15

The sedimentation characteristics of polysomal mRNA labelled in vitro by [5-3H]uridine and electrophoretic mobility of similar non-labelled mRNA of mouse plasmacytoma were studied. Rapidly labelled polysomal mRNA may be considered as mRNA on the basis of several independent but indirect tests. These mRNA's are localized in 18-6S region of sucrose gradient. Some part of radioactivity have been found in the ribosomal RNA. It was shown that there is 8-10 RNA fractions in sucrose gradient. The 16S and 12-14S fractions are isolated and partially purified by two- and three-fold centrifugation. Fractions homogenous in sucrose gradient were electrophoresed in PAAG-SDS and divided into several subfractions some of them being common for 16S and 12-14S. The number of non-crossover subfractions was about 2-3. Not less than 20 different main fractions of polysomal mRNA were determined in plasmacytoma cells on the basis of electrophoretic data.
Mol Biol (Mosk)
PMID:[mRNA fractions of mouse plasmacytoma cells]. 95 20


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>