5G00
CRYSTAL STRUCTURE OF A POTATO STI-KUNITZ BIFUNCTIONAL INHIBITOR OF SERINE AND ASPARTIC PROTEASES IN SPACE GROUP P4322 AND PH 7.4
Summary for 5G00
| Entry DOI | 10.2210/pdb5g00/pdb |
| Related | 5FZU 5FZY 5FZZ |
| Descriptor | KTI-A PROTEIN, 2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total) |
| Functional Keywords | hydrolase, sti-kunitz inhibitor, aspartic proteases, serine proteases, protease inhibitor, bi-functional protease inhibitor, hydrolase inhibitor, kunitz-type inhibitor |
| Biological source | SOLANUM TUBEROSUM (POTATO) |
| Total number of polymer chains | 1 |
| Total formula weight | 20747.71 |
| Authors | Guerra, Y.,Rudino-Pinera, E. (deposition date: 2016-03-16, release date: 2016-07-06, Last modification date: 2024-10-09) |
| Primary citation | Guerra, Y.,Valiente, P.A.,Pons, T.,Berry, C.,Rudino-Pinera, E. Structures of a bi-functional Kunitz-type STI family inhibitor of serine and aspartic proteases: Could the aspartic protease inhibition have evolved from a canonical serine protease-binding loop? J. Struct. Biol., 195:259-271, 2016 Cited by PubMed Abstract: Bi-functional inhibitors from the Kunitz-type soybean trypsin inhibitor (STI) family are glycosylated proteins able to inhibit serine and aspartic proteases. Here we report six crystal structures of the wild-type and a non-glycosylated mutant of the bifunctional inhibitor E3Ad obtained at different pH values and space groups. The crystal structures show that E3Ad adopts the typical β-trefoil fold of the STI family exhibiting some conformational changes due to pH variations and crystal packing. Despite the high sequence identity with a recently reported potato cathepsin D inhibitor (PDI), three-dimensional structures obtained in this work show a significant conformational change in the protease-binding loop proposed for aspartic protease inhibition. The E3Ad binding loop for serine protease inhibition is also proposed, based on structural similarity with a novel non-canonical conformation described for the double-headed inhibitor API-A from the Kunitz-type STI family. In addition, structural and sequence analyses suggest that bifunctional inhibitors of serine and aspartic proteases from the Kunitz-type STI family are more similar to double-headed inhibitor API-A than other inhibitors with a canonical protease-binding loop. PubMed: 27329566DOI: 10.1016/j.jsb.2016.06.014 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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