5LS0
Crystal structure of Inorganic Pyrophosphatase PPA1 from Arabidopsis thaliana
Summary for 5LS0
| Entry DOI | 10.2210/pdb5ls0/pdb |
| Related | 4lug |
| Descriptor | Soluble inorganic pyrophosphatase 1, MAGNESIUM ION, DI(HYDROXYETHYL)ETHER, ... (4 entities in total) |
| Functional Keywords | inorganic pyrophosphatase, hydrolase, ob-fold |
| Biological source | Arabidopsis thaliana (Mouse-ear cress) |
| Total number of polymer chains | 2 |
| Total formula weight | 41299.82 |
| Authors | Grzechowiak, M.,Sikorski, M.,Jaskolski, M. (deposition date: 2016-08-22, release date: 2017-09-13, Last modification date: 2024-01-17) |
| Primary citation | Grzechowiak, M.,Ruszkowski, M.,Sliwiak, J.,Szpotkowski, K.,Sikorski, M.,Jaskolski, M. Crystal structures of plant inorganic pyrophosphatase, an enzyme with a moonlighting autoproteolytic activity. Biochem.J., 476:2297-2319, 2019 Cited by PubMed Abstract: Inorganic pyrophosphatases (PPases, EC 3.6.1.1), which hydrolyze inorganic pyrophosphate to phosphate in the presence of divalent metal cations, play a key role in maintaining phosphorus homeostasis in cells. DNA coding inorganic pyrophosphatases from (PPA1) and (PPA1) were cloned into a bacterial expression vector and the proteins were produced in cells and crystallized. In terms of their subunit fold, PPA1 and PPA1 are reminiscent of other members of Family I soluble pyrophosphatases from bacteria and yeast. Like their bacterial orthologs, both plant PPases form hexamers, as confirmed in solution by multi-angle light scattering and size-exclusion chromatography. This is in contrast with the fungal counterparts, which are dimeric. Unexpectedly, the crystallized PPA1 and PPA1 proteins lack ∼30 amino acid residues at their N-termini, as independently confirmed by chemical sequencing. , self-cleavage of the recombinant proteins is observed after prolonged storage or during crystallization. The cleaved fragment corresponds to a putative signal peptide of mitochondrial targeting, with a predicted cleavage site at Val31-Ala32. Site-directed mutagenesis shows that mutations of the key active site Asp residues dramatically reduce the cleavage rate, which suggests a moonlighting proteolytic activity. Moreover, the discovery of autoproteolytic cleavage of a mitochondrial targeting peptide would change our perception of this signaling process. PubMed: 31371393DOI: 10.1042/BCJ20190427 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.83 Å) |
Structure validation
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