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Publication Abstract from PubMed

Complex cell-to-cell communication between the male pollen tube and the female reproductive organs is required for plant fertilization. A family of Catharanthus roseus receptor kinase 1-like (CrRLK1L) membrane receptors has been genetically implicated in this process. Here, crystal structures of the CrRLK1Ls ANXUR1 and ANXUR2 are reported at 1.48 and 1.1 A resolution, respectively. The structures reveal a novel arrangement of two malectin-like domains connected by a short beta-hairpin linker and stabilized by calcium ions. The canonical carbohydrate-interaction surfaces of related animal and bacterial carbohydrate-binding modules are not conserved in plant CrRLK1Ls. In line with this, the binding of chemically diverse oligosaccharides to ANXUR1 and HERCULES1 could not be detected. Instead, CrRLK1Ls have evolved a protein-protein interface between their malectin domains which forms a deep cleft lined by highly conserved aromatic and polar residues. Analysis of the glycosylation patterns of different CrRLK1Ls and their oligomeric states suggests that this cleft could resemble a binding site for a ligand required for receptor activation of CrRLK1Ls.

Crystal structures of two tandem malectin-like receptor kinases involved in plant reproduction.,Moussu S, Augustin S, Roman AO, Broyart C, Santiago J Acta Crystallogr D Struct Biol. 2018 Jul 1;74(Pt 7):671-680. doi:, 10.1107/S205979831800774X. Epub 2018 Jun 27. PMID:29968676^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.