3SYK
Crystal structure of the AAA+ protein CbbX, selenomethionine structure
Summary for 3SYK
| Entry DOI | 10.2210/pdb3syk/pdb |
| Related | 3SYL 3zuh |
| EMDB information | 1932 |
| Descriptor | Protein CbbX, SULFATE ION (3 entities in total) |
| Functional Keywords | photosynthesis, rubisco activase, aaa+ protein, calvin cycle, chaperone |
| Biological source | Rhodobacter sphaeroides |
| Total number of polymer chains | 2 |
| Total formula weight | 70761.28 |
| Authors | Mueller-Cajar, O.,Stotz, M.,Wendler, P.,Hartl, F.U.,Bracher, A.,Hayer-Hartl, M. (deposition date: 2011-07-18, release date: 2011-11-09, Last modification date: 2024-10-30) |
| Primary citation | Mueller-Cajar, O.,Stotz, M.,Wendler, P.,Hartl, F.U.,Bracher, A.,Hayer-Hartl, M. Structure and function of the AAA+ protein CbbX, a red-type Rubisco activase. Nature, 479:194-199, 2011 Cited by PubMed Abstract: Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyses the fixation of atmospheric CO(2) in photosynthesis, but tends to form inactive complexes with its substrate ribulose 1,5-bisphosphate (RuBP). In plants, Rubisco is reactivated by the AAA(+) (ATPases associated with various cellular activities) protein Rubisco activase (Rca), but no such protein is known for the Rubisco of red algae. Here we identify the protein CbbX as an activase of red-type Rubisco. The 3.0-Å crystal structure of unassembled CbbX from Rhodobacter sphaeroides revealed an AAA(+) protein architecture. Electron microscopy and biochemical analysis showed that ATP and RuBP must bind to convert CbbX into functionally active, hexameric rings. The CbbX ATPase is strongly stimulated by RuBP and Rubisco. Mutational analysis suggests that CbbX functions by transiently pulling the carboxy-terminal peptide of the Rubisco large subunit into the hexamer pore, resulting in the release of the inhibitory RuBP. Understanding Rubisco activation may facilitate efforts to improve CO(2) uptake and biomass production by photosynthetic organisms. PubMed: 22048315DOI: 10.1038/nature10568 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (3.08 Å) |
Structure validation
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