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

Degradation of messenger RNA from the lactose operon (lac mRNA) was measured during the inhibition of protein synthesis by chloramphenicol (CM) or of translation-initiation by kasugamycin (KAS). With increasing CM concentration mRNA decay becomes slower, but there is no direct proportionality between rates of chemical decay and polypeptide synthesis. During exponential growth lac mRNA is cleaved endonucleolytically (Blundell and Kennell, 1974). At a CM concentration which completely inhibits all polypeptide synthesis this cleavage is blocked. In contrast, if only the initiation of translation is blocked by addition of KAS, the cleavage rate as well as the rate of chemical decay are increased significantly without delay. These faster rates do not result from immediate degradation of the lengthening stretch of ribosome-free proximal message, since the full-length size is present and the same discrete message sizes are generated during inhibition. These results suggest that neither ribosomes nor translation play an active role in the degradative process. Rather, targets can be protected by the proximity of a ribosome, and without nearly ribosomes the probability of cleavage becomes very high. During normal growth there is a certain probability that any message is in such a vulnerable state, and the fraction of vulnerable molecules determines the inactivation rate of that species.
Mol Gen Genet 1978 Apr 06
PMID:Translation and mRNA decay. 34 50

Yeast chromatin, isolated by a rapid procedure contains in addition to histones H2A, H2B, H3 and H4 a fifth major basic protein. This fifth polypeptide is not an intrinsic component of the nucleosome structure. It has properties of both histone and nonhistone proteins and might represent an early form of histone H1 and of high mobility group nonhistone proteins of higher eukaryotes. Electron microscopic visualization of isolated yeast nucleosomes substaniates further the similarity of the chromatin structudre of this unicellular eukaryote to that of higher eukaryotes.
Mol Gen Genet 1978 May 31
PMID:Yeast chromatin: search for histone H1. 35 18

Saccharomyces cerevisiae 2-mum DNA and some of its restriction fragments were integrated in vector pCR1 ,pBR313 or pBR322 and their expression in Escherichia coli P678-54 minicells was analyzed. 2mum DNA inserted at the EcoRI site of pCR1 or pBR313 and at the PstI site of pBR322 promoted the synthesis of polypeptides of 48,000, 37,000, 35,000 and 19,000 daltons. The DNA regions coding for these polypeptides were mapped on the 2-mum DNA molecule by insertion of single EcoRI or HindIII restriction fragments and comparison of the polypeptides produced. For the synthesis of the 37,000 dalton polypeptide, intact sites RIB and H3 were required. The disappearance of the 37,000 dalton polypeptide on interruption of one of these sites by insertion of the vector, was correlated with the appearance of a polypeptide of 22,000 or 23,500 daltons respectively. The DNA sequence coding for the 37,000 daltons polypeptide, therefore, has to be located in the S-loop region close to or overlapping with the site RIB and H3. Assuming that the 22,000 and the 23,500 dalton polypeptides are truncated forms of the 37,000 dalton polypeptide, the last polypeptide can be exactly mapped. The polypeptide of 48,000 daltons was mapped to that half of the L-loop segment containing the sites H1 and H2. If, however, HindIII fragment H1-H2 was expressed, the 48,000 dalton polypeptide was lost and concomitantly a 43,000 dalton polypeptide appeared. We assume that this polypeptide results from early termination of the polypeptide of 48,000 daltons. The 35,000 and 9,000 dalton polypeptides were mapped to the S-loop region. The integrated inverted repeat sequence of yeast 2-mum Dna did not induce any detectable insert-specific polypeptide synthesis.
Mol Gen Genet 1978 Jun 01
PMID:Mapping of regions on cloned Saccharomyces cerevisiae 2-mum DNA coding for polypeptides synthesized in Escherichia coli minicells. 35 23

A detailed description of structural investigations of pepsin from 3.5 to 2.7 A resolution are given. The main attention is drawn to the conformation of the polypeptide backbone of the enzyme. The numbers of amino acid residues involved in the formation of various structural elements are listed. The structure of pepsin is similar to that of acid proteases isolated from lower organisms. The two domain structure of all acid proteases has a periodicity in the sequence of beta-segments and helices and a very specific symmetrical structure of each domain. This makes it possible to describe the structure of acid proteases in simple terms.
Mol Biol (Mosk)
PMID:[X-ray structural analysis of pepsin. V. Conformation of the main chain of the enzyme]. 35 68

Three new genes nifM, nifI and nifN have been mapped in the nif gene cluster of Klebsiella pneumoniae and a fourth gene nifJ has been confirmed as being a separate cistron. Polar nif mutations were obtained by transposition of Tn7 to plasmid pRD1, and of Tn5 and Tn10 to plasmid pMF100, a derivative of pRD1. Complementation analysis of the nif::Tn mutants led to the identification of at least six transcriptional units: nifB; nifA; nifJ; nifH, nifD and nifK; nifE and nifI; nifN, nifM and nifF. Biochemical and genetic evidence suggest that the three genes nifH, nifD and nifK, which are probably the structural genes for nitrogenase, belong to the same operon and are transcribed from nifH to nifK. A polypeptide with a molecular weight of approximately 120,000 is presumed to be the nifJ product.
Mol Gen Genet 1978 Sep 20
PMID:Polarity of mutations induced by insertion of transposons Tn5, Tn7 and Tn10 into the nif gene cluster of Klebsiella pneumoniae. 36 60

Temperature-sensitive mutants of an Escherichia coli K-12 strain PA3092 have been isolated following mutagenesis with nitrosoguanidine, and their ribosomal proteins analyzed by two-dimensional gel electrophoresis. This method was found to be very efficient in obtaining mutants with various structural alterations in ribosomal proteins. Thus a total of some 160 mutants with alterations in 41 different ribosomal proteins have so far been isolated. By characterizing these mutants, we could isolate not only those mutants with alterations in the structural genes for various ribosomal proteins, but also those with impairments in the modification of proteins S5, S18 and L12. Furthermore, a mutant has been obtained which apparently lacks the protein S20 (L26) with a concomitant reduction to a great extent of the polypeptide synthetic activity of the small subunit. The usefulness of these mutants in establishing the genetic architecture of the genes coding for the ribosomal proteins and their modifiers is discussed.
Mol Gen Genet 1978 Sep 20
PMID:Mutations affecting the structural genes and the genes coding for modifying enzymes for ribosomal proteins in Escherichia coli. 36 62

Polar mutations were obtained by integration of bacteriophage Mu c+ or Mu cts DNA into the Klebsiella pneumoniae nif genes located on plasmid pCE1, a derivative of pRD1. In addition, nif deletions were isolated from nif::Mu cts plasmids. Complementation data allowed the characterization of twelve nif cistrons, nine corresponding to previously identified genes. Polar effect of Mu DNA insertions suggested the existence of at least six transcription units: 1) nif K, nif D and nif H--2)nif A and nif L--3) nif E and a new gene--4) nif B--5) nif F--6) nif J. Nif K, nif D and nif H, which are most probably the structural genes for nitrogenase, seem to belong to the same operon transcribed from nif H to nif K. This was confirmed by SDS gel autoradiography of pulse labelled proteins. Moreover it was possible to identify, on the autoradiograms, a polypeptide which likely is the product of nif J and whose biosynthesis is under the control of nif A.
Mol Gen Genet 1978 Oct 04
PMID:Genetic and biochemical analysis of mutants induced by bacteriophage Mu DNA integration into Klebsiella pneumoniae nitrogen fixation genes. 36 77

Defective lambda transducing phages for the nalA region of the Escherichia coli chromosome were isolated from a lysogen in which lambda is inserted in the nearby glpT gene. The three classes of transducing phages designated lambdanrdA, lambdaubiG, and lambdadnalA contained bacterial DNA extending from glpT through nrdA, ubiG, and nalA, respectively. The bacterial genes are in the left arm of the lambda chromosome. Of the eleven polypeptides coded by lambdadnalA that were resolved by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate only one was not also specified by lambdadubiG. This 105,000 dalton polypeptide is the nalA gene product. The electorphoretic mobility and isoelectric point of this protein were unaffected by a nalA mutation (nalA48) that confers nalidixic acid resistance. Temperature-sensitive and amber mutations in the nalA gene were isolated using a lambdadnalA48 lysogen which is heterodiploid for nalA. The conditional lethality of these mutations proves that nalA is an essential locus.
Mol Gen Genet 1978 Nov 29
PMID:Lambda transducing phages for the nalA gene of Escherichia coli and conditional lethal nalA mutations. 36 82

Conservation of polypeptide fold and mode of ligand binding is frequently found within proteins of related function. Examples illustrating this phenomenon are taken from NAD linked enzymes, nucleotide binding proteins, polysaccharide binding proteins, heme binding proteins and enzymes with essential Fe--S complexes or zinc atoms.
Mol Cell Biochem 1978 Nov 16
PMID:The taxonomy of binding sites in proteins. 36 87

Diuron-resistance, DIU (Colson et al., 1977), antimycin-resistance, ANA (Michaelis, 1976; Burger et al., 1976), funiculosin-resistance, FUN (Pratje and Michaelis, 1977; Burger et al., 1977) and mucidin-resistance, MUC (Subik et al., 1977) are each coded by a pair of genetic loci on the mit DNA of S. cerevisiae. In the present paper, these respiratiory-competent, drug-resistant loci are localized relative to respiratory-deficient BOX mutants deficient in coenzyme QH2-cytochrome c reductase (Kotylak and Slonimski, 1976, 1977) using deletion and recombination mapping. Three drug-resistant loci possessing distinct mutated allelic forms are distinguished. DIU1 is allelic or closely linked to ANA2, FUN1 and BOX1; DIU2 is allelic or closely linked to ANA1, MUC1 and BOX4/5; MUC2 is allelic to BOX6. The high recombinant frequencies observed between the three loci (13% on the average for 33 various combinations analyzed) suggest the existence of either three genes coding for three distinct polypeptides or of a single gene coding for a single polypeptide but subdivided into three easily separable segments. The resistance of the respiratory-chain observed in vitro in the drug-resistant mutants and the allelism relationships between respiratory-competent, drug-resistant loci and coQH2-cyt c reductase deficient, BOX, loci strongly suggest that each of the three drug-resistant loci codes for a structural gene-product which is essential for the normal coQH2-cyt c reductase activity and is obviously a good candidate for a gene product of the drug-resistant loci mapped in this paper. Polypeptide length modifications of cytochrome b were observed in mutants deficient in the coQH2-cyt c red and localized at the BOX1, BOX4 and BOX6 genetic loci (Claisse et al., 1977, 1978) which are precisely the loci allelic to drug resistant mutants as shown in the present work. Taken together these two sets of data provide a strong evidence in favor of the idea that there exist three non contiguous segments of the mitochondrial DNA sequence which code for a single polypeptide sequence of cytochrome b. In each segment mutations which modify the polypeptide sequence can occur leading to the loss (BOX mutants) or to a modification (drug resistant mutants) of the enzyme activity.
Mol Gen Genet 1979 Jan 02
PMID:Genetic localization of diuron- and mucidin-resistant mutants relative to a group of loci of the mitochondrial DNA controlling coenzyme QH2-cytochrome c reductase in Saccharomyces cerevisiae. 36 93


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