PMC

Localization of FBA4. (A) FBA4-EYFP fusion; YFP fluorescence is shown in yellow. (B) EYFP-FBA4 fusion; YFP fluorescence is shown in green, chlorophyll autofluorescence in red. Bars, 2 μm.

Protein maximum likelihood phylogeny of class I FBA. Numbers at the nodes indicate approximate likelihood-ratio test support values.

Protein maximum likelihood phylogeny of class I bacterial-like cytosolic FBA. Numbers at the nodes indicate approximate likelihood-ratio test support values.

Protein maximum likelihood phylogeny of class II A FBA. Numbers at the nodes indicate approximate likelihood-ratio test support values.

Colocalization of plastid FBA-YFP with CA1-CFP. (A) FBAC1-EYFP + CA1-CFP, (B) FBAC5-EYFP + CA1-CFP. Chlorophyll autofluorescence is shown in red, YFP fluorescence in green, and CFP fluorescence in blue. Left image: CFP fluorescence, center: YFP fluorescence, right image: combined fluorescence. Bars, 2 μm.

Localization of plastid FBA-EYFP fusion proteins. (A) FBAC1-EYFP, (B) FBAC2-EYFP, (C) FBAC5-EYFP. On the left light microscopy image, chlorophyll autofluorescence is shown in red and YFP fluorescence in green. Bars, 2 μm.

Localization of FBA3-EYFP fusion proteins. On the left light microscopical image center: YFP fluorescence in yellow and chlorophyll autofluorescence is shown in red. YFP fluorescence is shown in green on the right in order to more easily distinguish the chloroplast. Bars, 2 μm.

Localization of Phaeodactylum tricornutum FBAC5 by transmission electron microscopy. A clone expressing the FBAC5_EYFP fusions was fixed, and the intracellular EYFP was immunolocalized by means of an anti-GFP antibody. The antibody bound strongly to an intraplastidial structure in FBAC5_EYFP transformant cells. Chloroplasts (C) and pyrenoids (Pyr) and gold particles detected with electron microscopy are indicated. Unlabeled cells did not show any labeling (data not shown).

FBA activity in Phaeodactylum tricornutum (UTEX646) cells grown for 5 days in Fe deplete and replete medium. Enzymatic activity is given as mU/mg total cellular soluble protein. The measurements were performed in either presence or absence of EDTA to measure class I FBA activity or total FBA activity, respectively.

Expression of Phaeodactylum tricornutum FBA genes according to their normalized frequency of observation in a range of cDNA libraries representing different environmental conditions (). Normalized expression values were obtained by dividing the number of FBA ESTs in the different libraries by the total number of sequences generated for the different libraries. The R value was defined in , an R value above 12 indicates nonspurious differences in the EST frequency across libraries (i.e., differential expression). The features of the 15 libraries have been published elsewhere (; ; ). Si− = f/2 with artificial seawater, no Si added; Si+ = 350 μM metasilicate; Oval = Oval strain CCAP1052/1B; Triradiate = Triradiate strain NEPCC640; Blue light = Cells grown in the dark for 48 h and subjected to blue light for 1 h; Tropical = Tropical strain CCMP633 grown at a suboptimal temperature of 18 °C; N replete = 1.12 mM chemostat culture; NO3 starved = 50 μM in chemostat culture for 12 days; Urea adapted = 50 μM Urea; Fe deplete = 5 nM Iron; Low DD = 0.5 μg/ml 2E,4E-decadienal for 6 h; High DD = 5 μg/ml 2E,4E-decadienal for 6 h (for a full description of culture conditions, see ).