Membrane Organization of Anacystis Nidulans Following Iron Deprivation and Heme Deficiency

Abstract

The cyanobacterium, Anacystis nidulans, has been used to study the synthesis, insertion, and assembly of lipid-protein complexes into photosynthetic membranes. A topological model of these membranes was recently presented (J.A. Guikema, L.A. Sherman, 1982), as were the changes in membrane architecture induced by iron deficiency (J.A. Guikema, L.A. Sherman, 1983b). Iron deficiency yielded cells with a reduced thylakoid content, and containing reduced concentrations of photosynthetically important polypeptides. Polypeptides with heme, iron, or chlorophyll as ligands were especially influenced. Importantly, the addition of iron to deficient cultures caused the resynthesis of thylakoids, and provided a method for studying membrane biosynthesis in these cells.