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G Feix

Publications and source records attributed to G Feix.

At least 37 records · Page 2Linked to original sources
PubMed1989

Analysis of distal flanking regions of maize 19-kDa zein genes.

Two genomic fragments from maize, each containing a 19-kDa zein gene with extensive flanking regions, have been sequenced and examined by computer-aided analysis and Southern blotting techniques. Sequence analysis of the distal flanking sequences has revealed interesting sequence motifs, some not seen before. In particular, four nearly identical, G + C-rich, 17 to 21-bp perfect palindromes were found clustered in a 133-bp stretch lying 2 kb upstream from the zein-coding region in the genomic clone pMS2. These palindromic sequences exhibit other interesting features, including a precise spatial organization with respect to each other, and their proximity to several other repeated motifs in the same region. Southern blot analysis indicates that these palindromes, or closely related sequences, are found frequently in the maize genome. Possible secondary structures for the palindrome units are presented, which resemble functionally important sequences found upstream from other eukaryotic genes.

Base Sequence↗
PubMed1989

A nuclear casein type II kinase from maize endosperm phosphorylating HMG proteins.

A casein kinase of the type II was isolated and enriched from nuclear lysates of maize endosperm tissue. The kinase activity requires 10 mM Mg2+ for maximal activity, can utilize either ATP or GTP as phosphate donors and is inhibited by polyamines, heparin and monovalent cations. A substrate specificity of the kinase activity towards specific nuclear proteins is indicated by its phosphorylation of high mobility group (HMG) proteins isolated from endosperm and its lack of accepting histones as protein substrates.

Animals↗
PubMed1989

Specific binding of nuclear proteins to the promoter region of a maize nuclear rRNA gene unit.

The external spacer region of a nuclear rRNA gene unit of maize was analyzed for binding of nuclear proteins and revealed binding to the promoter region and to the 200-base pair repeat elements upstream of the promoter. The promoter binding site was further characterized by DNase I and exonuclease III foot-printing as well as by gel shift and South-Western experiments, revealing the binding of several proteins. Competition experiments indicate that the protein which interacts with the repeat units also binds to the promoter region. A model for the combined action of both binding regions in the regulation of transcription is presented.

Binding, Competitive↗
PubMed1987

Binding of a nuclear factor to a consensus sequence in the 5' flanking region of zein genes from maize.

The genomic organization of the zein structural genes and of regulatory loci influencing their expression suggests that control of zein gene expression will involve interactions between cis elements in the flanking DNA sequences and products from trans-acting genes. The interaction between fragments from the 5' flanking region of a zein gene and specific, double-stranded oligonucleotides with crude nuclear extracts from maize endosperm have been studied by nitrocellulose filter binding, gel retention and DNase I footprinting assays. Specific binding of a nuclear factor was observed and the exact position of the protein binding site was determined. The 22-nt binding site included 14 bp of a 15-bp sequence conserved in all zein genes.

Consensus Sequence↗
PubMed1986

Occurrence of 9 homologous repeat units in the external spacer region of a nuclear maize rRNA gene unit.

A 14 kb maize DNA fragment carrying nuclear rRNA genes and spacer regions was isolated and characterised by restriction enzyme mapping. A complete 3020 bp long external spacer region was sequenced and revealed 9 tandemly arranged 200 bp long repeat units with high homology. The repeat units lie upstream from two prominent S1 mapping signals. The sequence of a typical repeat unit is compared to a corresponding 130 bp long wheat repeat unit. The possible functional relevance of the repeat units is discussed.

Base Sequence↗
PubMed1986

Accurate in vitro splicing of two pre-mRNA plant introns in a HeLa cell nuclear extract.

Two plant introns along with flanking exon sequences have been isolated from an amylase gene of wheat and a legumin gene of pea and cloned behind the phage SP6 promoter. Pre-mRNAs produced by in vitro transcription with SP6 RNA polymerase were tested for their ability to be spliced in a HeLa cell nuclear extract. The plant introns were accurately spliced and the predicted splice junctions were used. Lariat RNAs were observed as both intermediates and final products during the splicing reaction. The branch points were mapped to adenosine residues lying within sequences that showed good homology to the animal branch point consensus. Consensus sequences for the 5' and 3' splice junctions and for putative branch point sequences of plants were derived from an analysis of 168 plant intron sequences.

Amylases↗
PubMed1984

Transcription from maize storage protein gene promoters in yeast.

Genes coding for zein storage proteins of maize of the 19 000- and 21 000-dalton size classes were integrated into chromosome II of the yeast Saccharomyces cerevisiae. Using the transformed yeast strains as an in vivo transcription system it was shown that promoter regions of the zein genes of both size classes were accurately recognized. In particular, the zein mRNA synthesis in yeast starts at the same nucleotide positions used in the maize endosperm. A difference in the promoter activity between the 21 000- and the 19 000-dalton zein genes was observed.

Cloning, Molecular↗
PubMed1983

A zein gene of maize is transcribed from two widely separated promoter regions.

The zein proteins are the major storage proteins of maize endosperm. They are made from large amounts of zein RNAs of several distinct sizes, ranging from the small 900 base final size RNA to precursor forms of over 3800 bases. The 900 base mRNA and the smallest precursor mRNA of 1800 bases are transcribed from two distinct promoter regions, P1 and P2. In vitro transcription of a maize genomic clone containing a zein gene pML 1 allowed both promoters to be mapped. The sequence of pML 1, covering the two promoter regions, contained consensus transcription start sequences at both of the predicted promoters. S1 mapping with RNA prepared from maize endosperm showed that both P1 and P2 are active in vivo as double starts.

Amino Acid Sequence↗
PubMed1982

Isolation and characterization of maize genes coding for zein proteins of the 21000 dalton size class.

Cloning in lambda gt WES phage of EcoRI fragments from maize seedlings DNA led to the isolation of four fragments containing genes coding for 21000 dalton zein proteins. The zein genes, identified by electron microscopic analysis, do not contain intervening sequences detectable by this method. The flanking sequences were analyzed by restriction sites mapping and hybridization and showed areas of homology between each other and with sequences surrounding a previously isolated gene of the 19000 dalton zein class.

Cloning, Molecular↗
PubMed1979

Cloning of double stranded DNAs derived from polysomal mRNA of maize endosperm: isolation and characterisation of zein clones.

Starting from polysomal RNA of developing maize endosperm and applying the cloning procedure of integrating dsDNA into the Pst I site of plasmid pBR 322, clones containing sequences complementary to endosperm mRNAs were obtained. 25 per cent of these clones were identified as containing zein specific DNA sequences which hybridized either with the zein mRNA coding for the 22 000 Mr protein or with the zein mRNA coding for the 19 000 Mr protein. The zein-specific DNA inserts of the recombinant plasmids were further characterized by restriction enzyme analysis.

DNA, Recombinant↗
PubMed1978

Electrophoretic fractionation and translation in vitro of poly(rA)-containing RNA from maize endosperm. Evidence of two mRNAs coding for zein protein.

In the search for individual mRNAs coding for particular zein proteins, polysomal RNA was isolated from the endosperm of 22-days post-pollination maize kernels. This RNA was enriched for poly(rA)-containing RNAs and then submitted to preparative polyacrylamide gel electrophoresis under denaturing conditions. After electrophoresis, RNA fractions were eluted from the polyacrylamide gel and analyzed for zein mRNA activity by translation in vitro in the wheat germ system. The wheat germ system had previously been optimized for accurate translation of zein mRNAs. By a gel-electrophoretic analysis of immunoprecipitated products from the translation reactions in vitro, it could conclusively be shown that the endosperm of developing maize kernels contains two separable mRNAs for zein, one coding for the 22000-Mr protein and one coding for the 19000-Mr protein.

Electrophoresis, Polyacrylamide Gel↗
PubMed1976

Terminal riboadenylate transferase from Escherichia coli. Characterization and application.

Catalytic properties of terminal riboadenylate transferase from Escherichia coli and the products of the enzymic reaction were investigated. The kinetic analysis revealed that the reaction obeys the sequential ordered bi-bi mechanism. The application of conditions elaborated in this study resulted in the synthesis of products of defined size and efficient primer utilization. The tRNA(rA)n obtained was a good template for the synthesis of complementary DNA with reverse transcriptase.

Adenosine Monophosphate↗
PubMed1975

Initiation specificity of the poly(cytidylic acid)-dependent Qbeta replicase activity.

The initiation specificity of RNA synthesis catalysed by the poly(C)-dependent Qbeta replicase activity was investigated with various synthetic ribopolymers as template. It was found that the initiation efficiency of a series of oligo(C) with various chain lengths is proportional to the template size. Synthetic riboheteropolymers containing cytidylic acid were accepted as templates only if they contained at their 3' end a cytidylic acid sequence of more than 5 nucleotides. Such an oligocytidylate sequence served also as an initiator sequence for copying the non-cytidylic-acid-containing part of the heterotemplate. RNA synthesis always began with the incorporation of GTP, even if the 3'-terminating nucleotide of the template was not cytidylic acid.

Base Sequence↗