Structure Basis of the Phytoplasma Effector Sap05 Recognition Specificities to Plant Rpn10 in Ubiquitin-Independent Protein Degradation

• DOI: 10.2139/ssrn.4580460
• Publication Date: 2023-09-26T00:33:51Z
• Authors: Liying Zhang; Yunxiang Du; Qian Qu; Qingyun Zheng
• Keywords: Degradation; Protein Degradation; Phytoplasma

Besides traditional ubiquitin-dependent proteasome degradation, thousands of eukaryotic proteins more than previously appreciated could undergo ubiquitin-independent proteasomal degradation (UbInPD). A pathogen-encoded effector protein SAP05 secreted by phytoplasma, hijack hostage Rpn10 subunit derived from Arabidopsis thaliana and target the GATA BINDING FACTOR (GATA) or SQUAMOSA-PROMOTER PROTEIN-LIKE (SPL) transcription factors without ubiquitin additional shuttle factors. To explain how bypassing pathway, we have determined crystal structure complex between Aster Yellows witches'-broom phytoplasma onion yellow SAP05, which showed a unknown recognition interface. Sequence alignment structural biological evidence that this interaction is highly conserved in various homologs, suggesting general mode plant infection. After docking to proteasome, was near adenosine triphosphatase (ATPase) central pore enough submit substrate process, suggested molecular glue-like role bridge close ATPase proteasomes for direct degradation.