2 a 2,3-di-O-phytanyl-sn-glycerophospholipid + 2 AH2 + 4 S-adenosyl-L-methionine = a glycerol dibiphytanyl glycerol tetraether phospholipid + 4 5'-deoxyadenosine + 4 L-methionine + 2 A + 4 H(+) — reaction