Insights into the function of RifI2: structural and biochemical investigation of a new shikimate dehydrogenase family protein.

The shikimate dehydrogenase (SDH) family consists of enzymes with diverse roles in secondary metabolism. The two most widespread members of the family, AroE and YdiB, function in amino acid biosynthesis and quinate catabolism, respectively. Here, we have determined the crystal structure of an SDH homolog belonging to the RifI class, a group of enzymes with proposed roles in antibiotic biosynthesis.

Structural and biochemical investigation of two Arabidopsis shikimate kinases: the heat-inducible isoform is thermostable.

The expression of plant shikimate kinase (SK; EC 2.7.1.

Genes co-expressed with CPSAR1 identified using ATTED-II.

Identification of interacting proteins will help to investigate further the relationship between CPSAR1 and the vesicle transport system or the ribosomes. Thus, we adopted a bioinformatic approach, using the publicly available Arabidopsis thaliana trans-factor and cis-element prediction database, ATTED-II (http://atted.jp/), to identify putative protein interactors.

Exploiting antigenic diversity for vaccine design: the chlamydia ArtJ paradigm.

We present an interdisciplinary approach that, by incorporating a range of experimental and computational techniques, allows the identification and characterization of functional/immunogenic domains. This approach has been applied to ArtJ, an arginine-binding protein whose orthologs in Chlamydiae trachomatis (CT ArtJ) and pneumoniae (CPn ArtJ) are shown to have different immunogenic properties despite a high sequence similarity (60% identity). We have solved the crystallographic structures of CT ArtJ and CPn ArtJ, which are found to display a type II transporter fold organized in two α-β domains with the arginine-binding region at their interface.

The chloroplast protein CPSAR1, dually localized in the stroma and the inner envelope membrane, is involved in thylakoid biogenesis.

Thylakoid biogenesis is a crucial step for plant development involving the combined action of many cellular actors. CPSAR1 is shown here to be required for the normal organization of mature thylakoid stacks, and ultimately for embryo development. CPSAR1 is a chloroplast protein that has a dual localization in the stroma and the inner envelope membrane, according to microscopy studies and subfractionation analysis.

In vivo studies on the roles of Tic55-related proteins in chloroplast protein import in Arabidopsis thaliana.

The Tic55 (Translocon at the inner envelope membrane of chloroplasts, 55 kDa) protein was identified in pea as a putative regulator, possibly linking chloroplast protein import to the redox state of the photosynthetic machinery. Two Tic55 homologs have been proposed to exist in Arabidopsis: atTic55-II and AtPTC52 (Protochlorophyllide-dependent Translocon Component, 52 kDa; has also been called atTic55-IV). Our phylogenetic analysis shows that atTic55-II is an ortholog of psTic55 from pea (Pisum sativum), and that AtPTC52 is a more distant homolog of the two.

The VLCFA elongase gene family in Arabidopsis thaliana: phylogenetic analysis, 3D modelling and expression profiling.

As precursors of wax compounds, very long chain fatty acids participate in the limitation of non-stomatal water loss and the prevention of pathogen attacks. They also serve as energy storage in seeds and as membrane building blocks. Their biosynthesis is catalyzed by the acyl-CoA elongase, a membrane-bound enzymatic complex containing four distinct enzymes (KCS, KCR, HCD and ECR).

Profiling candidate genes involved in wax biosynthesis in Arabidopsis thaliana by microarray analysis.

Plant epidermal wax forms a hydrophobic layer covering aerial plant organs which constitutes a barrier against uncontrolled water loss and biotic stresses. Wax biosynthesis requires the coordinated activity of a large number of enzymes for the formation of saturated very-long-chain fatty acids and their further transformation in several aliphatic compounds. We found in the available database 282 candidate genes that may play a role in wax synthesis, regulation and transport.