Enzyme co-localization with transketolase, xylulose-5-P 3-epimerase and phosphoriboisomerase in pea leaf chloroplasts

Nearest neighbor analyses of immunocytolocalization experiments indicate that glyceraldehyde-3-P dehydrogenase subunit B, aldolase and phosphoriboisomerase are located close to transketolase, that glyceraldehyde-3-P dehydrogenase and phosphoribulokinase are located close to xylulose-5-P 3-epimerase, and that phosphoriboisomerase is located close to phosphoribulokinase and to Rubisco, in the pea leaf chloroplast stroma. Spatial organization of these enzymes may be important for efficient carbon metabolism in photosynthetic organisms. In contrast, neither fructose bisphosphatase, sedoheptulose bisphosphatase, the A subunit of glyceraldehyde-3-P dehydrogenase or xylulose-5-P 3-epimerase is co-localized with transketolase.