1,721,186 research outputs found
Genomic-assisted identification of genes involved in secondary growth in Arabidopsis utilising transcript profiling of poplar wood-forming tissues
No full textDespite the importance of secondary growth in plants, relatively few genes
regulating this process have been identified to date. By using data from detailed
transcript profiling of the poplar wood-forming tissues, 150 genes that are
differentially expressed within the zone of secondary growth were identified.
In order to determine the possible function of these poplar genes, potential
Arabidopsis thaliana orthologs were identified and gene knockout lines anal-
ysed. Three selection filters were used to identify the most likely orthologous
genes using poplar and Arabidopsis sequence comparisons, expression pro-
filing in secondary thickened Arabidopsis hypocotyls and global expression
analysis of Arabidopsis tissues. Three genes encoding AtCSLA2 (At5g22740),
the AtGUT1 GT47 glycosyltransferase (At1g27440) and a protein with no
proposed function AtUNKA (At4g27435) were selected for further detailed
analysis of their role in secondary growth in Arabidopsis. The presented
genome-based approach using both poplar and Arabidopsis systems provides
powerful means towards assigning biological functions to enzymes with
poorly understood biochemical activity, such as AtCSLA2 and AtGUT1, as
well as for proteins with no known function
The cellulolytic enzyme system of Trichoderma reesei:Molecular cloning, characterization and expression of the cellobiohydrolase genes: Dissertation
No full textIn this study, gene technology has been used to investigate the cellulolytic enzymes of the filamentous fungus, Trichoderma reesei.A genomic library of T. reesei was constructed using a phage lambda vector and the chromosomal copies of the two cellobiohydrolase genes were isolated.An RNA isolation method, facilitating the synthesis of long cDNAs, was adapted for filamentous fungi.Efficient cDNA cloning method involving blunt end ligation to plasmid vectors was developed and used to construct a cDNA library of T. reesei.From this library the cDNA copies of the genes coding for two cellobiohydrolases and an endoglucanase were identified.Sequence analysis of the cellulolytic enzyme genes led to the identification of two separate domains in these enzymes.Comparison of the deduced primary structures to other carbohydrate degrading enzymes suggests that the glycosylated terminal domains have a role in substrate binding.Analysis of the regulatory regions of the cbh2 gene revealed multiple transcription initiation sites and comparison of the chromosomal and cDNA copies of the cellulolytic enzyme genes revealed the presence of two or more short introns.Expression of the cbhl cDNA was optimized in the heterologous host, Escherichia coli.The highest expression levels were obtained by fusing the mature CBH I to either the E. coli ß-galactosidase or a short N- terminal leader peptide of the bacteriophage lambda Cro protein.The Cro-CBH I fusion protein was produced as intracellular aggregates devoid of enzymatic activity and the CBH I activity was restored by renaturation.Computer aided molecular modeling was used to study the folding of the proposed active site region of CBH I.The model obtained does not conflict with the idea that this region in CBH I has a similar tertiary structure to the active site of the phage T4 lysozyme.The enzyme-substrate interactions, proposed on the basis of the model, can be tested using site directed mutagenesis
Engineering of enzymes of carbohydrate metabolism
No full textProgress in the past year includes the engineering of xylose isomerases to improve their performances in industry. In addition, the publication of the first three-dimensional structure of a cellulolytic enzyme, and significant improvement in the resolution of α-amylase structures now permit detailed studies of the enzymology and engineering of these important enzymes
Crystalline cellulose degradation:New insight into the function of cellobiohydrolases
No full textCellulose is an important industrial raw material and a source of renewable energy. The crystalline structure of cellulose is biodegradable by the combined activities of many different enzymes. Cellobiohydrolases, the key cellulases, have extended tunnel-shaped active sites. Owing to the design of their active-site tunnels, they do not make cuts within cellulose chains but release cellobiose from the chain ends. Cellobiohydrolases may therefore prove to be useful for achieving subtle modifications of fiber properties in paper or textiles without the loss of fiber strength commonly observed with other cellulases.</p
Jokaiselle mahdollisuus kansainvälistymiseen
No full textKoulutus on pienen, viennistä riippuvaisen maan menestyksen ehdoton edellytys. Suomalaisen osaamisjärjestelmän on kyettävä kouluttamaan uuden aikakauden osaajia, joilla on kyky ja into toimia kansainvälisessä vuorovaikutuksessa maailmanlaajuisesti. Koulutuksen kansainvälistyminen luo pohjan Suomen ja suomalaisten yritysten kansainväliselle kilpailukyvylle globaalissa osaamiskilpailussa.
Tämän selvityksen tavoitteena oli tehdä esitys toimista, joilla koulujen, ammattioppilaitosten ja lukioiden oppilaiden ja korkeakoulujen opiskelijoiden kansainvälinen liikkuvuus voidaan kaksinkertaistaa vuoteen 2030 mennessä, ottaen huomioon liikkuvuutta tukevat ohjelmat, kestävän kehityksen mukaiset tavoitteet ja liikkuvuuden uudet muodot.
Suomalaisten opiskelijoiden ja opettajien kansainvälinen liikkuvuus on verraten hyvällä tasolla mutta käytännön toimenpiteiden kirjo on suuri. Opiskelijaliikkuvuuden kaksinkertaistamiseksi Suomessa tarvitaan kansallinen tiekartta selkeine määrällisine tavoitteineen, kansainvälistymisinstrumenttien ja rahoituskanavien koordinoitu hallinta ja riittävä resursointi oppilaitosten kansainvälistymisen mahdollistamiseksi eri asteilla. Erityisen tärkeää on saada kansainvälistymiskoulutuksen piiriin ne ryhmät, jotka yhä ovat aliedustettuina, esimerkiksi pojat, aikuisopiskelijat sekä toimintarajoitteiset opiskelijat.
Oppilas- ja opiskelijaliikkuvuuden kaksinkertaistaminen edellyttää myös, että kaikilla koulutusasteilla lisätään systemaattisesti kansallista koordinaatiota hyvien käytäntöjen jakamiseksi ja yleistämiseksi, että kansainvälistymisen tukipalveluja ja niiden rahoitusta vahvistetaan ja että alueellista yhteistyötä lisätään pienempien kuntien saamiseksi kansainvälistymiskoulutuksen piiriin
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