Cross-species investigation of the functions of the Rhodobacter PufX polypeptide and the composition of the RC-LH1 core complex

► Dimeric RC-LH1 complexes were be isolated from Rba. azotoformans and Rba. changlensis. ► RC-LH1 dimers could not be isolated from Rba. capsulatus or Rba. vinaykumarii. ► Chimeric RC-LH1 complexes could be isolated as monomers but not as dimers. ► Whether RC-LH1 dimers can be isolated is determined by both PufX and LH1 proteins. ► The findings tease apart different functions of PufX in different Rhodobacter species.