Subdomain XI of Kinase Domain of Protein Kinase A

Subdomain XI is the last of the subdomains present in the kinase domain protein kinase A. It extends to about residue 297 of the protein, and to the end of the kinase domain. The boundary between the kinase domain and the rest of the protein is still not very well defined, so the residue number is approximate.

The most important feature of the subdomain is the nearly invariant Arg280 that lies between alpha helices H and I. For serine/threonine kinases, such as protein kinase A, the consenus motif His-x-Aromatic-hydrophobic is found 9-13 postions down from the nearly invariant Arg. This motif seems to define the C-terminal boundary of the kinase domain In protein kinase A, the residues from about 300 to the C-terminus of the protein are outside of the kinase domain