RANK [SEP] found in taxon
repeat domains (CRDs). It shares 40% amino acid identity with CD40. RANK is encoded on human chromosome 18q22.1. It shows 85% homology between mouse and human homologues.
There are two monomers of RANK related by noncrystallographic 2-fold symmetry perpendicular to the long axis of the molecules in the asymmetric unit. RANK contains four CRDs spanning a length of 100 Angstroms which makes it the longest member of the TNFR family to date.
The binding of RANKL to RANK trimerizes the receptor and activates a signaling pathway. The
Taxon in disguise
In bacteriology, a taxon in disguise is a species, genus or higher unit of biological classification whose evolutionary history reveals has evolved from another unit of similar or lower rank, making the parent unit paraphyletic. This happens when rapid evolution makes a new species appear radically different from the ancestral group, so that it is not (initially) recognised as belonging to the parent phylogenetic group, leaving the latter an evolutionary grade.
While the term is from bacteriology, parallel examples are found throughout the tree of