Mechanism of self/nonself-discrimination in Brassica self-incompatibility.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33004803.
- Also identified by DOI 10.1038/s41467-020-18698-w and PMC identifier 7530648.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Self-incompatibility (SI) is a breeding system that promotes cross-fertilization. In Brassica, pollen rejection is induced by a haplotype-specific interaction between pistil determinant SRK (S receptor kinase) and pollen determinant SP11 (S-locus Protein 11, also named SCR) from the S-locus. Although the structure of the B. rapa S<sub>9</sub>-SRK ectodomain (eSRK) and S<sub>9</sub>-SP11 complex has been determined, it remains unclear how SRK discriminates self- and nonself-SP11. Here, we uncover the detailed mechanism of self/nonself-discrimination in Brassica SI by determining the S<sub>8</sub>-eSRK-S<sub>8</sub>-SP11 crystal structure and performing molecular dynamics (MD) simulations. Comprehensive binding analysis of eSRK and SP11 structures reveals that the binding free energies are most stable for cognate eSRK-SP11 combinations. Residue-based contribution analysis suggests that the modes of eSRK-SP11 interactions differ between intra- and inter-subgroup (a group of phylogenetically neighboring haplotypes) combinations. Our data establish a model of self/nonself-discrimination in Brassica SI.
Medical subject headings
- Brassica rapa
- Plant Breeding
- Plant Proteins
- Protein Kinases