title: The sema domain.
abstract: The sema domain was first defined from sequence by Kolodkin and colleagues in the early 1990s, and constitutes the distinctive structural and functional element of semaphorins, their plexin receptors and the receptor tyrosine kinases MET and RON, three protein families with major roles in development, tissue regeneration and cancer. Recently determined crystal structures of two semaphorins (SEMA3A and SEMA4D) and the MET receptor have shown that the sema domain consists of a highly conserved variant form of the seven-blade beta-propeller fold. The structures, however, also suggest differences between these families with respect to the mode of dimerisation and the regions of the domain involved in ligand-receptor interactions. This reflects the considerable plasticity and adaptation of the sema domain in order to meet different binding requirements, properties that may underlie the vast array of ligand-receptor specificities and functions of the semaphorin superfamily.
authors.affiliation: MRC Centre, Hills Road, Cambridge CB2 2QH, UK. egherard@mrc-lmb.cam.ac.uk
authors.forename: Ermanno
authors.initials: E
authors.lastname: Gherardi
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Love
authors.forename: Robert M
authors.initials: RM
authors.lastname: Esnouf
authors.forename: E Yvonne
authors.initials: EY
authors.lastname: Jones
mesh_terms: D000818:Animals; D001665:Binding Sites; D006801:Humans; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry* / Q000378:metabolism*; D039961:Semaphorins / Q000737:chemistry* / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D039961:Semaphorins; D020794:Receptor Protein-Tyrosine Kinases