PsRubisco maintains the most common hexadecameric Rubisco form. (a) The refined subunits comprising the L4S4 asymmetric unit viewed along the fourfold symmetry axis. L subunits are shown in blue and S subunits are shown in red. (b) The L8S8 biologically relevant hexadecameric complex viewed along the twofold symmetry axis. The L-subunit symmetry mates are shown in grey, with the asymmetric unit refined L subunits shown in blue and both refined and symmetry-related S subunits shown in red.