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41.
var1 Gene on the mitochondrial genome of Torulopsis glabrata 总被引:5,自引:0,他引:5
We have cloned and sequenced a region of the Torulopsis glabrata mitochondrial genome homologous to the Saccharomyces cerevisiae var1 gene (var1Sc). An open reading frame that could encode a protein of 339 amino acids was found with 72.7% amino acid and 85.3% nucleotide sequence homology to the S. cerevisiae var1 gene. The T. glabrata gene (var1Tg) is transcribed yielding two stable RNAs, a more abundant 13.5 S RNA and a less abundant 18 S species. We have also identified a candidate for a T. glabrata var1 protein among mitochondrial translation products labeled in isolated mitochondria. The var1Tg gene is even more A + T-rich (93%) than var1Sc (89.6%) and has conserved the strong codon bias of var1Sc. Major differences between the two sequences were found. Significant among these are that no GC clusters are found in var1Tg and the sequences surrounding each of the sites where known polymorphisms exist in var1Sc have deletions at the corresponding sites in var1Tg. These data are discussed with respect to possible origins of these var1 genes and translocation of GC clusters in S. cerevisiae mitochondrial DNA. 相似文献
42.
Milan Höfer Klaas Nicolay George Robillard 《Journal of bioenergetics and biomembranes》1985,17(3):175-182
The electrochemical gradient of protons,
, was estimated in the obligatory aerobic yeastRhodotorula glutinis in the pH0 range from 3 to 8.5. The membrane potential, , was measured by steady-state distribution of the hydrophobic ions, tetraphenylphosphonium (TPP+) for negative above pH0 4.5, and thiocyanate (SCN–) for positive below pH0 4.5. The chemical gradient of H+ was determined by measuring the chemical shift of intracellular Pi by31P-NMR at given pH0 values. The values of pHi increased almost linearly from 7.3 at pH0 3 to 7.8 at pH0 8.5. In the physiological pH0 range from 3.5 to 6,
was fairly constant at values between 17–18 KJ mol–1, gradually decreasing at pH0 above 6. In deenergized cells, the intracellular pHi decreased to values as low as 6, regardless of whether the cell suspension was buffered at pH0 4.5 or 7.5. There was no membrane potential detectable in deenergized cells. 相似文献
43.
A method for efficient gene isolation from phage lambda gt11 libraries: use of antisera to denatured, acetone-precipitated proteins 总被引:3,自引:0,他引:3
Experience with cloning pseudorabies virus (PRV) DNA in the lambda gt11 phage vector has shown that there are special requirements for the antisera used in screening the libraries, in addition to the requirement that the antisera recognize proteins on a Western blot. Initial screening of a lambda gt11 library of sheared PRV DNA fragments in Escherichia coli for expression of PRV antigens using PRV hyperimmune antisera was unsuccessful. It was only after screening the library with antisera raised against PRV proteins eluted from sodium dodecyl sulfate (SDS)-polyacrylamide (PA) gels that positive results were obtained. These "gel-slice" antisera (GSA) were equivalent in potency to hyperimmune antisera in standard immunoassays (including ELISA, immunoprecipitation, Western blots, and neutralization of virus), but only the GSA could recognize PRV fusion proteins expressed by recombinant lambda gt11 phage. This difference was seen despite the fact that hyperimmune antisera performed satisfactorily on Western blots of denatured PRV-infected cell extracts. These results show that the efficiency of screening expression libraries in E. coli can be improved if antibodies are raised against denatured proteins. 相似文献
44.
Restriction endonuclease EcoO109 from Escherichia coli H709c with heptanucleotide recognition site 5'-PuG/GNCCPy 总被引:1,自引:0,他引:1
A new restriction endonuclease, EcoO109, has been isolated from Escherichia coli H709c by polyethyleneimine (PEI) precipitation, DEAE-cellulose chromatography and heparin agarose chromatography. The yield was high, more than 3000 units/g of wet cells. The EcoO109 endonuclease recognizes and cleaves a nucleotide sequence of (formula: see text), in the presence of 10 mM Mg2+. The enzyme will be useful for structural analysis and molecular cloning of DNA because of the stability, high yield and easy handling of the producer strain. 相似文献
45.
S Millar D C Hayward C A Read M J Browne R V Santelli F Garcia Vallejo M T Pueyo A Zaha D M Glover F J Lara 《Gene》1985,34(1):81-86
We have constructed a library of recombinant phage containing DNA from salivary gland chromosomes of Rhynchosciara americana. We have isolated phage from this library that carry sequences homologous to cDNA clones that hybridize in situ to the DNA puffs at the polytene chromosome regions C3 and C8. This has enabled us to demonstrate a 16-fold amplification of the genomic DNA sequences at these regions during DNA-puffing. At the C8 site there is a sequence element that has characteristics of 'scrambled' moderately repetitive DNA. This is located within 3 kb from the gene encoding a 1.95-kb mRNA. We have assayed restriction fragments from the two DNA puffs for Ars activity in yeast. The only strong Ars activity is associated with a part of the moderately repetitive DNA element from the C8 puff which is not present at this site in all animals. 相似文献
46.
The araBAD operon of Salmonella typhimurium LT2. I. Nucleotide sequence of araB and primary structure of its product, ribulokinase 总被引:6,自引:0,他引:6
Hybrid plasmids containing the araBAD operon of Salmonella typhimurium LT2 were characterized by Southern blot and genetic analyses. The nucleotide sequence of araB was determined. The araB gene product, ribulokinase (EC 2.7.1.16), was purified and the results of amino acid composition analysis and partial amino acid sequence are in agreement with predictions from the DNA sequence. Ribulokinase is 569 amino acid residues long and has a calculated Mr of 61 793. Ribulokinase shares significant homology with xylulose kinase from Escherichia coli. Codon usage in the araB gene does not favor those codons which have intermediate codon-anticodon binding energy. 相似文献
47.
48.
Nonrandom insertion of Tn5 into cloned human adenovirus DNA 总被引:4,自引:0,他引:4
49.
Abstract cAMP-dependent phosphoprotein changes were determined using 1-dimensional SDS-gel electrophoresis in a cAMP-requiring yeast mutant ( Saccharomyces cerevisiae AM18). During cAMP starvation, the yeast cells accumulated 3 32 P-labeled bands with M r / 72000, 54000, and 37000. The M r / 72000 protein was the most prominent phosphorylated protein. After the readdition of cAMP, these phosphoproteins lost their 32 P-label while phosphoproteins with M r / 76000, 65000, 56000 and 30000 were accumulated. Similar phosphoprotein changes were also detected in cdc35 at the nonpermissive temperature, but not in wildtype (A363A) or cdc7 strains of S. cerevisiae . 相似文献
50.