Figure 2.

CPE is the general SPP of chloroplasts. (A) Processing of [³⁵S]methionine-labeled preLHCPII wild type (wt) and a processing site mutant. (B) Processing of [³⁵S]methionine-labeled preRBCS, preRBCA, preCF₁γ, preOEE1, prePC, preACP1, preDHS1, and preHSP21. (C) Processing of [³⁵S]methionine-labeled preCPE. (D) Processing of preFD labeled with [³⁵S]methionine (Met*) and [³⁵S]cysteine (Cys*), respectively. Lanes 1, radiolabeled precursor. Lanes 2, precursor incubated with control extract of induced E. coli cells carrying pBEX5BA lacking the CPE insert, except incubation of preACP was done with magnetic beads that were preincubated with the control extract. Lanes 3, processing with CPE-B extract, except processing of preACP was carried out with immobilized CPE-B due to a proteolytic activity in the E. coli extract that degraded preACP. Lanes 4, processing with chloroplast extract. p, Precursor; i, intermediate; m, mature; tp, transit peptide.