The KIND (kinase non-catalytic C-lobe domain) is a putative protein interaction domain, which has been identified as being similar to the C-terminal protein kinase catalytic fold (C lobe) (see <PDOC00100>). Its presence at the N-terminus of signalling proteins and the absence of the active site residues in the catalytic and activation loops suggest that it folds independently and is likely to be non-catalytic. The occurence of the domain only in metazoa implies that it has evolved from the catalytic protein kinase domain into an interaction domain possibly by keeping the substrate-binding features [1,2].

Some proteins known to contain a KIND domain are listed below:

• Animal Spir proteins. In the central region they contain a WH2 domain (see <PDOC51082>) cluster, which is known to bind actin. The C-terminal region encodes a modified FYVE zinc-finger domain, which directs the subcellular localization of the proteins.
• Animal non-receptor phosphatase type 13 (PTP type 13), which also contains a FERM domain (see <PDOC00566>), PDZ domains (see <PDOC50106>) and a tyrosine specific protein phosphatase (see <PDOC00323>).
• Vertebrate very KIND (VKIND or KIAA1768), a signalling protein specifically expressed in the nervous system of vertebrates. It has two KIND domains in the N-terminal half, and a guanine nucleotide exchange factor domain for Ras-like GTPases (RasGEF) at the C-terminal end with a structural domain attached at its N-terminal (RasGEFN) (see <PDOC00594>).

The profile we developed covers the entire KIND domain.