التفاصيل البيبلوغرافية
| العنوان: |
Cryo-EM structure of the Agrobacterium tumefaciens type IV secretion system-associated T-pilus reveals stoichiometric protein-phospholipid assembly |
| المؤلفون: |
Kreida, Stefan, Narita, Akihiro, Johnson, Matthew D., Tocheva, Elitza I., Das, Anath, Ghosal, Debnath, Jensen, Grant J. |
| سنة النشر: |
2023 |
| المجموعة: |
Caltech Authors (California Institute of Technology) |
| الوصف: |
Agrobacterium tumefaciens is a plant pathogen that causes crown gall disease by the horizontal transfer of oncogenic DNA that is integrated into the host's genome. The conjugation is mediated by the conjugative VirB/D4 type 4 secretion system (T4SS). A. tumefaciens T4SS assembles an extracellular filament, the T-pilus, that is involved in the formation of a mating pair between A. tumefaciens and the recipient plant cell by a not fully understood mechanism. Here, we present a 3 Ã… cryo-EM structure of the T-pilus, solved by helical reconstruction. Our structure reveals that the T-pilus comprises the major pilin protein VirB2 and phosphatidylglycerol (PG) phospholipid at a 1:1 stoichiometric ratio with 5-start helical symmetry. We further show that PG-headgroups and the positively charged Arg 91 residues of VirB2 protomers form extensive electrostatic interactions in the lumen of the T-pilus. Mutagenesis of Arg 91 destabilized the VirB2 protein and completely abolished pilus formation. While our T-pilus structure shows architectural similarity with previously published conjugative pili structures, positively charged sidechains protrude into the lumen and the lumen is narrower, raising questions whether the T-pilus is a conduit for ssDNA transfer. We also show that the VirB2 subunits in T-pilus filament are not cyclic, as previously thought. ; The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. We thank Dr. Songye Chen, Caltech cryo-EM facility for assistance during data collection; Dr. Tsui-Fen Chou, Dr. Brett Lomenick and Dr. Jeff Jones from Caltech Proteome Exploration Laboratory for conducting the protein mass-spec analysis. We also thank Dr. Kevin Williams and UCLA Lipidomics for performing lipid extraction, lipid data collection and giving valuable advice in lipidomic experimental design and data interpretation. This project was funded by a National Institutes of Health grant (R01 AI127401 to G.J.J), a National Health and ... |
| نوع الوثيقة: |
report |
| اللغة: |
unknown |
| العلاقة: |
https://resolver.caltech.edu/CaltechAUTHORS:20230323-670848000.1Test; https://doi.org/10.1101/2022.09.25.509369Test; oai:authors.library.caltech.edu:fmx62-ehp59; eprintid:120324; resolverid:CaltechAUTHORS:20230322-366935000.8 |
| DOI: |
10.1101/2022.09.25.509369 |
| الإتاحة: |
https://doi.org/10.1101/2022.09.25.509369Test |
| حقوق: |
info:eu-repo/semantics/openAccess ; Other |
| رقم الانضمام: |
edsbas.DFD719BE |
| قاعدة البيانات: |
BASE |
