Localisation of CP43 in single molecules of photosystem 2 using protein deletion and scanning tunnelling microscopy

Abstract

Scanning tunnelling microscopy of intact D1/D2/CP47/CP43 photosystem 2 (PS2) core complexes and CP43-deleted D1/D2/CP47 core complexes shows definitively that the CP43 subunits reside at the ends of the dimeric core complex. The CP43-removal procedure produces CP43-deleted cores with minimal conformational distortion to the D1/D2/CP47 residual core complex. There was excellent agreement between the X-ray and STM structures for the intact core complex, and between the STM image for the CP43-deleted core complex and the X-ray model with the components assigned to CP43 omitted.