RESUMO
As part of the European Scientists Sequencing Arabidopsis program, a contiguous region (396607 bp) located on chromosome 4 around the APETALA2 gene was sequenced. Analysis of the sequence and comparison to public databases predicts 103 genes in this area, which represents a gene density of one gene per 3.85 kb. Almost half of the genes show no significant homology to known database entries. In addition, the first 45 kb of the contig, which covers 11 genes, is similar to a region on chromosome 2, as far as coding sequences are concerned. This observation indicates that ancient duplications of large pieces of DNA have occurred in Arabidopsis.
Assuntos
Duplicação Gênica , Genes de Plantas , Proteínas de Homeodomínio/genética , Proteínas Nucleares/genética , Proteínas de Plantas/genética , Arabidopsis/genética , Proteínas de Arabidopsis , Sequência de Bases , Mapeamento Cromossômico , Mapeamento de Sequências Contíguas , DNA de Plantas , Genoma de Planta , Íntrons , Computação Matemática , Dados de Sequência Molecular , Família MultigênicaRESUMO
As a contribution to the European Scientists Sequencing Arabidopsis (BIOTECH ESSA) project, a contig of almost 40kb has been sequenced at the extreme top of chromosome 1, around the Arabidopsis thaliana gene coding for a member of the 1-aminocyclopropane-1-carboxylate synthesis gene family. The region contains, besides the ACS1 gene itself, 10 putative genes, all new for Arabidopsis. Among these are three genes encoding kinases, a late embryogenesis-abundant protein, a MADS box-containing protein, a dehydrogenase, and a Myb-related transcription factor. In addition, six cDNAs have been sequenced that correspond to this region.
Assuntos
Arabidopsis/genética , Cromossomos/genética , DNA de Plantas/genética , Proteínas Proto-Oncogênicas c-myb , Arabidopsis/química , Proteínas de Arabidopsis , Mapeamento Cromossômico , Clonagem Molecular , DNA de Plantas/química , Proteínas de Ligação a DNA/genética , Expressão Gênica/genética , Genes de Plantas/genética , Genoma de Planta , Proteínas de Domínio MADS , Dados de Sequência Molecular , Oxirredutases/genética , Fosfotransferases/genética , Proteínas de Plantas/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/genéticaRESUMO
As part of the European Union program of European Scientist Sequencing Arabidopsis (ESSA), the DNA sequence of a 24.053-bp insert of cosmid clone CC17J13 was determined. The cosmid is located on chromosome 1 at the PFL locus (position 30 cM). Analysis of the sequence and comparison to public databases predicts seven genes in this area, thus approximately one gene every 3.3 kb. Three cDNAs corresponding to genes in this region were also sequenced. The homologies and/or possible functions of the (putative) genes are discussed. Proteins encoded by genes in this region include a polyadenylate-binding protein (PAB-3) and a GTP-binding protein (Rab7) as well as a novel protein, possibly involved in double-stranded RNA unwinding and apoptosis. Intriguingly, the gene encoding the PAB-3 protein, which is very specifically expressed, is flanked by putative matrix attachment regions.
Assuntos
Arabidopsis/genética , Mapeamento Cromossômico , Proteínas rab de Ligação ao GTP , Sequência de Bases , DNA Complementar , DNA de Plantas/química , Bases de Dados como Assunto , Europa (Continente) , Proteínas de Ligação ao GTP/genética , Genoma de Planta , Dados de Sequência Molecular , Proteínas de Ligação a Poli(A) , Proteínas de Ligação a RNA/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , proteínas de unión al GTP Rab7RESUMO
A full-length cDNA and the corresponding At-P5S gene encoding the first enzyme of the proline biosynthetic pathway, the delta 1-pyrroline-5-carboxylate (P5C) synthetase, were isolated in Arabidopsis thaliana. The At-P5S cDNA encodes a protein of 717 amino acids showing high identity with the P5C synthetase of Vigna aconitifolia. Strong homology is also found at the N-terminus to bacterial and yeast gamma-glutamyl kinase and at the C-terminus to bacterial gamma-glutamyl phosphate reductase. Putative ATP- and NAD(P)H-binding sites are suggested in the At-P5S protein. The transcribed region of the At-P5S gene is 4.8 kb long and contains 20 exons. Southern analysis suggests the presence of only one At-P5S gene in the A. thaliana genome mapped at the bottom of the chromosome two. Expression analysis of At-P5S in different organs reveals abundant At-P5S transcripts in mature flowering plant. Rapid induction of the At-P5S gene followed by accumulation of proline was observed in NaCl-treated seedlings suggesting that At-P5S is osmoregulated.
Assuntos
Arabidopsis/genética , Mapeamento Cromossômico , Genes de Plantas , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , 1-Pirrolina-5-Carboxilato Desidrogenase , Aldeído Oxirredutases/química , Sequência de Aminoácidos , Arabidopsis/enzimologia , Sequência de Bases , Southern Blotting , Clonagem Molecular , Primers do DNA/química , Primers do DNA/genética , DNA Complementar/genética , Regulação da Expressão Gênica de Plantas/genética , Glutamato-5-Semialdeído Desidrogenase , Zíper de Leucina/genética , Dados de Sequência Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/química , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/metabolismo , Fosfotransferases (Aceptor do Grupo Carboxila)/química , Reação em Cadeia da Polimerase , Prolina/biossíntese , Estrutura Secundária de Proteína , Alinhamento de Sequência , Cloreto de Sódio/farmacologia , Transcrição Gênica/genéticaRESUMO
The soil fungus Trichoderma harzianum is a mycoparasitic fungus known for its use as a biocontrol agent of phytopathogenic fungi. Among other factors, Trichoderma produces a series of antibiotics and fungal cell wall-degrading enzymes. These enzymes are believed to play an important role in mycoparasitism. Among the hydrolytic enzymes, we have identified a basic proteinase (Prb1) which is induced by either autoclaved mycelia, fungal cell wall preparation or chitin; however, the induction does not occur in the presence of glucose. The proteinase was purified and biochemically characterized as a serine proteinase of 31 kDa and pI 9.2. Based on the sequence of three internal peptides, synthetic oligonucleotide probes were designed. These probes allowed subsequent isolation of a cDNA and its corresponding genomic clone. The deduced amino acid sequence indicates that the proteinase is synthesized as a pre-proenzyme and allows its classification as a serine proteinase. Northern analysis shows that the induction of this enzyme is due to an increase in the corresponding mRNA level.
