Precursors to small subunits (SSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) and apoproteins of light-harvesting chlorophylla/bbinding protein (LHCPII) in photosystem II were synthesized in vitro by expressing pine (Pinus thunbergiiParl.) cDNA clones encoding these proteins. The precursors to pine SSU and LHCPII were post-translationally transported into spinach chloroplasts, processed into mature size, and localized in only stroma and thylakoid membranes, respectively. The pine SSU was tightly integrated into spinach Rubisco; however, the pine LHCPII was not found in the light-harvesting chlorophyll–protein complex. These results suggest that a common biogenesis pathway of nuclear-encoded chloroplast proteins is present both in gymnosperms and in angiosperms.