Biosynthesis and secretion of the microbial sulfated peptide RaxX and binding to the rice XA21 immune receptor.
Proc Natl Acad Sci U S A
; 116(17): 8525-8534, 2019 04 23.
Article
in En
| MEDLINE
| ID: mdl-30948631
ABSTRACT
The rice immune receptor XA21 is activated by the sulfated microbial peptide required for activation of XA21-mediated immunity X (RaxX) produced by Xanthomonas oryzae pv. oryzae (Xoo). Mutational studies and targeted proteomics revealed that the RaxX precursor peptide (proRaxX) is processed and secreted by the protease/transporter RaxB, the function of which can be partially fulfilled by a noncognate peptidase-containing transporter component B (PctB). proRaxX is cleaved at a Gly-Gly motif, yielding a mature peptide that retains the necessary elements for RaxX function as an immunogen and host peptide hormone mimic. These results indicate that RaxX is a prokaryotic member of a previously unclassified and understudied group of eukaryotic tyrosine sulfated ribosomally synthesized, posttranslationally modified peptides (RiPPs). We further demonstrate that sulfated RaxX directly binds XA21 with high affinity. This work reveals a complete, previously uncharacterized biological process bacterial RiPP biosynthesis, secretion, binding to a eukaryotic receptor, and triggering of a robust host immune response.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptide Hydrolases
/
Peptides
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Plant Proteins
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Bacterial Proteins
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Protein Serine-Threonine Kinases
Language:
En
Journal:
Proc Natl Acad Sci U S A
Year:
2019
Document type:
Article