ABSTRACT
Zhang et al., (1999) have made a detailed study of the cotranslational assembly of Dl protein. Their results show that the assembly of new copy of Dl takes place cotranslationally since the nascent Dl chains interact with D2 during the translation elongation itself. Further, CP 47 may be associated with D2 at this stage, while CP 43 assembles with the core complex after the Dl protein translation is completed. Cotranslational incorporation of newly-synthesized Dl into PS II highlights the tight coordination between Dl translation and incorporation into pre-existing core complexes. During Dl elongation and translocation process, TMs of nascent Dl protein exit laterally from translocon and start interacting with other PS II core proteins. These events can be depicted in the model for synthesis, insertion and assembly of Dl into PS II. The small cp SecY translocon plays an active role in directing the Dl nascent chain to their final location in PS II.
