Solution structure and physiological requirements for Psb27 in synechocystis sp. PCC 6803

Abstract

Photosystem II (PS II) is a membrane-embedded protein complex that has a highly regulated assembly pathway. A number of proteins that interact transiently with PS II have been identified. One of these proteins, Psb27, is a cyanobacterial lipoprotein that binds to inactive PS II monomers and is involved in the biogenesis of the active PS II dimer. We have solved the solution structure of Psb27 and have identified a group of conserved residues that potentially form an interaction with PS II [Mabbitt PD, Rautureau GJP, Day CL, Wilbanks SM, Eaton-Rye JJ, Hinds MG (2009) Biochemistry 48: 8771-8773]. Despite the conservation of Psb27 across plants and cyanobacteria, APsb27 Synechocystis sp. PCC 6803 cells lack a phenotype when grown under standard laboratory conditions. To assess Psb27 function, we have identified conditions where the ΔPsb27 mutant cannot grow photoautotrophically.