4AEC
Crystal Structure of the Arabidopsis thaliana O-Acetyl-Serine-(Thiol)- Lyase C
Summary for 4AEC
| Entry DOI | 10.2210/pdb4aec/pdb |
| Descriptor | CYSTEINE SYNTHASE, MITOCHONDRIAL, PYRIDOXAL-5'-PHOSPHATE, ACETATE ION, ... (5 entities in total) |
| Functional Keywords | lyase, cysteine synthesis, assimilatory sulfate reduction, sulfide, plant inorganic sulfur uptake |
| Biological source | ARABIDOPSIS THALIANA |
| Total number of polymer chains | 2 |
| Total formula weight | 92433.79 |
| Authors | Feldman-Salit, A.,Wirtz, M.,Lenherr, E.D.,Throm, C.,Hothorn, M.,Scheffzek, K.,Hell, R.,Wade, R.C. (deposition date: 2012-01-09, release date: 2012-02-22, Last modification date: 2023-12-20) |
| Primary citation | Feldman-Salit, A.,Wirtz, M.,Lenherr, E.D.,Throm, C.,Hothorn, M.,Scheffzek, K.,Hell, R.,Wade, R.C. Allosterically Gated Enzyme Dynamics in the Cysteine Synthase Complex Regulate Cysteine Biosynthesis in Arabidopsis Thaliana. Structure, 20:292-, 2012 Cited by PubMed Abstract: Plants and bacteria assimilate sulfur into cysteine. Cysteine biosynthesis involves a bienzyme complex, the cysteine synthase complex (CSC), which consists of serine-acetyl-transferase (SAT) and O-acetyl-serine-(thiol)-lyase (OAS-TL) enzymes. The activity of OAS-TL is reduced by formation of the CSC. Although this reduction is an inherent part of the self-regulation cycle of cysteine biosynthesis, there has until now been no explanation as to how OAS-TL loses activity in plants. Complexation of SAT and OAS-TL involves binding of the C-terminal tail of SAT in one of the active sites of the homodimeric OAS-TL. We here explore the flexibility of the unoccupied active site in Arabidopsis thaliana cytosolic and mitochondrial OAS-TLs. Our results reveal two gates in the OAS-TL active site that define its accessibility. The observed dynamics of the gates show allosteric closure of the unoccupied active site of OAS-TL in the CSC, which can hinder substrate binding, abolishing its turnover to cysteine. PubMed: 22325778DOI: 10.1016/J.STR.2011.11.019 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.4 Å) |
Structure validation
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