Spinach Major Light-Harvesting Complex
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The Light Harvesting Complex-II (LHC-II)
as it's name implies,is a major light-harvesting complex of photos II.
In green plants this is the major solar energy collector, and is the most prevalent and essential membrane protein in chloroplasts.
It is located in the thylakoid membrane and binds half of the thylakoid chlorophyll molecules.
Each monomer of this trimer is made up of 232 amino acids, 13-15 chlorophyll As and
chlorophyll B molecules, 3-4 caretonoids, and 1 bound phospholipid.
When selecting the links below, reorient the structure to the original orientation if you manually moved it.
For more information see
Biochemistry Online: Chapter
8D - Photosynthesis and the Light r Reaction
II. General Structure
Cartoon Structure and Space-fill looking at the plane of the membrane
Notice the alpha helices are located in the middle of the molecule
Cartoon Structure and Space-fill looking down the plane of the membrane
Notice the alpha helices running through the membrane plane
III. Protein Subunits
Subunit 1 (red)
Subunit 2 (orange)
Subunit 3 (green)
Chlorophylls/Cartinoids on one of the subunits
This shows both chlorophyll a and chlorophyll b, as well as the carotenoids.
Notice that the molecule is largely made up of chlorophyll and caretonoids, and the protein just seems to be there to support them.