Figure 4.

LHC proteins and their evolution. One-helix proteins (like HLIP) acquired a second helix resulting in two-helix proteins (like SEPs). The two-helix proteins underwent internal gene duplication event leading to a four-helix protein (like PsbS). From the loss of the fourth-helix, the three-helix proteins (like ELIPs and LHCs) are evolved. The arrow marks indicate (A), Gain of helix 2; (B), internal duplication; (C), loss of helix 4. At-Arabidopsis thaliana L.; Os-Oryza sativa L.