The ascorbate peroxidase-related protein: insights into its functioning in Chlamydomonas and Arabidopsis.

We review the newly classified ascorbate peroxidase-related (APX-R) proteins, which do not use ascorbate as electron donor to scavenge HO. We summarize recent discoveries on the function and the characterization of the APX-R protein of the green unicellular alga and the land plant . Additionally, we conduct analyses on the conserved MxxM motif, present in most of the APX-R protein in different organisms, which is proposed to bind copper.

Iron‑sulfur cluster synthesis in plastids by the SUF system: A mechanistic and structural perspective.

About 50 proteins expressed in plastids of photosynthetic eukaryotes ligate iron‑sulfur (Fe-S) clusters and ensure vital functions in photosynthesis, sulfur and nitrogen assimilation, but also in the synthesis of pigments, vitamins and hormones. The synthesis of these Fe-S clusters, which are co- or post-translationally incorporated into these proteins, relies on several proteins belonging to the so-called sulfur mobilization (SUF) machinery. An Fe-S cluster is first de novo synthesized on a scaffold protein complex before additional late-acting maturation factors act in the specific transfer, possible conversion and insertion of this cluster into target recipient proteins.

Heterotrophy Compared to Photoautotrophy for Growth Characteristics and Pigment Compositions in Batch Cultures of Four Green Microalgae.

Four strains of green microalgae (, , , and ) were compared to determine growth and pigment composition under photoautotrophic or heterotrophic conditions. Batch growth experiments were performed in multicultivators with online monitoring of optical density. For photoautotrophic growth, light-limited (CO-sufficient) growth was analyzed under different light intensities during the exponential and deceleration growth phases.

APX2 Is an Ascorbate Peroxidase-Related Protein that Regulates the Levels of Plastocyanin in Chlamydomonas.

The function of ascorbate peroxidase-related (APX-R) proteins, present in all green photosynthetic eukaryotes, remains unclear. This study focuses on APX-R from Chlamydomonas reinhardtii, namely, ascorbate peroxidase 2 (APX2). We showed that apx2 mutants exhibited a faster oxidation of the photosystem I primary electron donor, P700, upon sudden light increase and a slower re-reduction rate compared to the wild type, pointing to a limitation of plastocyanin.

Ascorbate Peroxidase 2 (APX2) of Chlamydomonas Binds Copper and Modulates the Copper Insertion into Plastocyanin.

Recent phylogenetic studies have unveiled a novel class of ascorbate peroxidases called "ascorbate peroxidase-related" (APX-R). These enzymes, found in green photosynthetic eukaryotes, lack the amino acids necessary for ascorbate binding. This study focuses on the sole APX-R from referred to as ascorbate peroxidase 2 (APX2).