Kegg Pathway: Ascorbate and aldarate metabolism

Bacteriol Virusol Parazitol Epidemiol. 2007 Jan-Jun; 52(1-2): 51-7
Corcionivoschi N

After isolation in 1970s, Campylobacter jejuni become the most commonly recognized cause of bacterial gastroenteritis in man. In animals is frequently found in bovines on ovines. Publishing of the genome sequence of Campylobacter jejuni 11168 (Parkhill, 2000) revealed the presence of only one cytochrome P450 in an operon involved in sugar and cell surface biosynthesis. The gene name is Cj1411c, is 1359 bp long and encodes 453 aa. The sequence is strictly conserved in Campylobacter jejuni RM221. Similarities with two cytochrome P450s, one form Silicobacter sp. and one form Poloromonas sp., were identified. These two enzymes are known to be involved in Ascorbate and aldarate metabolism. The recombinant construct allowed the expression of active P450 enzyme with a 450 nm peak when binds CO. The protein was purified in proportion of approximately 70%. By deleting the P450 gene from the Campylobacter jejuni 11168 genome clear changes in cell morphology were identified cells becoming wider and shorter. The capsular sugar profile of the NCI strain reveals the presence of arabinose which was not found in the wild type strain.

Planta. 2006 Apr; 223(5): 948-64
Hewezi T, Petitprez M, Gentzbittel L

The early stage of embryo development is a critical step in plant production. To identify genes with potential roles in the early sunflower seed development, a cDNA microarray approach was employed. We developed a thematic cDNA microarray containing clones representing high sequence similarities with known or predicted Arabidopsis genes implicated in different metabolic and signal transduction pathways. This 800-element cDNA array was used to compare the expression patterns in leaves and immature embryos (2 mm and 6 mm). Statistical analysis, using two-step ANOVA, revealed that 143 cDNA clones can be considered as differentially expressed. Of these, 62 clones were found to be up-regulated in leaves, 81 in embryos whereas only seven clones displayed increased level of mRNA in the 6 mm embryos when compared with 2 mm embryos. The differentially expressed clones are distributed among many metabolic and signal transduction pathways. For example, genes related to fatty acid metabolism and amino acid biosynthesis exhibited preferential expression patterns in immature embryos. Also, clones potentially encoding enzymes involved in the metabolism of Ascorbate and aldarate, pyruvate, propanoate and inositol, and citrate cycle were found to be up-regulated in embryos. In contrast, cDNA clones putatively involved in energy metabolism were more abundant in leaves than embryos. Clones encoding potential signal transduction components including receptors, protein kinases, protein phosphatases, and transcription factors were also identified, with preferential expression profiles in immature embryos. The expression patterns derived from this study provide initial characterization of metabolic pathways and signalling transduction networks occurring in the early stage of sunflower seed development.