RCSBProteinDataBank | Happy New Year from the RCSB PDB @RCSBProteinDataBank | Uploaded December 2017 | Updated October 2024, 4 days ago.
Cyano-bacteria obtain energy from photosynthesis. To optimize their life processes and energy production during the illuminated portion of the day, they utilize a circadian system. The animation presents a simplified view of the protein-protein interactions in the cyano-bacterial circadian system using the PDB structures 5n8y and 2gbl.
At the center of the clock is a large hexamer called KaiC (navy blue). During the day, KaiA (orange and red) is bound to the C-terminal domain of KaiC (facing the back in this view) stimulating it to bind ATP (purple and yellow), and to add phosphate groups (yellow) to itself. At dawn, KaiB (cyan) inhibits this phosphorylation process by binding to KaiC and by sequestering KaiA. During the night, KaiC becomes dephosphorylated, and by dusk, KaiA and KaiB detach from KaiC. As the day progresses, KaiA binds to the C-terminal domain of KaiC and the cycle begins again.
Read the Molecule of the Month on Circadian Clock Proteins (pdb101-beta.rcsb.org/motm/97) to learn how they measure time in our cells.
Explore the proteins shown in this animation in 3D at
rcsb.org/pdb/explore/explore.do?structureId=5n8y and
rcsb.org/pdb/explore/explore.do?structureId=2gbl
Cyano-bacteria obtain energy from photosynthesis. To optimize their life processes and energy production during the illuminated portion of the day, they utilize a circadian system. The animation presents a simplified view of the protein-protein interactions in the cyano-bacterial circadian system using the PDB structures 5n8y and 2gbl.
At the center of the clock is a large hexamer called KaiC (navy blue). During the day, KaiA (orange and red) is bound to the C-terminal domain of KaiC (facing the back in this view) stimulating it to bind ATP (purple and yellow), and to add phosphate groups (yellow) to itself. At dawn, KaiB (cyan) inhibits this phosphorylation process by binding to KaiC and by sequestering KaiA. During the night, KaiC becomes dephosphorylated, and by dusk, KaiA and KaiB detach from KaiC. As the day progresses, KaiA binds to the C-terminal domain of KaiC and the cycle begins again.
Read the Molecule of the Month on Circadian Clock Proteins (pdb101-beta.rcsb.org/motm/97) to learn how they measure time in our cells.
Explore the proteins shown in this animation in 3D at
rcsb.org/pdb/explore/explore.do?structureId=5n8y and
rcsb.org/pdb/explore/explore.do?structureId=2gbl
