Figure 4.

Representative CRP1 RIP-Chip Data.

(A) Immunoblots probed with the affinity-purified CRP1 antibody used in the RIP-chip assays. The left panel shows an immunoblot of chloroplast stroma from wild-type and crp1 mutant seedlings. Cross-reacting proteins are indicated with asterisks. The right panel shows an immunoblot of an α-CRP1 immunoprecipitation involving wild-type stroma; an immunoprecipitation with a different antibody (α-OE23) is shown as a negative control. IgGs in the immunoprecipitates are detected by the secondary antibody used to probe the immunoblot.

(B) Histograms showing the distribution of enrichment ratios in representative experimental and control CRP1 RIP-chip assays. Gray bars show the distribution of ratios for all array elements and are drawn to the frequency scale at left. Solid lines show the distribution for replicate spots overlapping the petA 5′ UTR (fragments 113 and 114) and the psaC 5′ UTR (fragments 233 and 235); the positions of these fragments are diagrammed in Figure 6C. Dashed lines show the distribution for spots corresponding to fragments 139, 142, 169, and 194, which derive from the petB, rpl2, and rps12 genes. The line plots are drawn to the frequency scale at right.