7my4

Publication Abstract from PubMed

Protein interaction domains can create unique macromolecular complexes that drive evolutionary innovation. By combining bioinformatic and phylogenetic analyses with structural approaches, we have discovered that the docking and dimerization (D/D) domain of the protein kinase A regulatory (PKA-R) subunit is an ancient and conserved protein fold. An archetypal function of this module is to interact with A-kinase anchoring proteins (AKAPs) that facilitate compartmentalization of this key cell signaling enzyme. Homology searching reveals that D/D domain proteins comprise a superfamily with eighteen members that function in a variety of molecular and cellular contexts. Further in silico analyses indicates that D/D domains segregate into subgroups on the basis of their similarity to type I or type II PKA-R subunits. The sperm autoantigenic protein 17 (SPA17) is a prototype of the type II or R2D2 subgroup that is conserved across metazoan phyla. We determined the crystal structure of an extended D/D domain from SPA17 (amino acids 1-75) at 1.72 A resolution. This revealed a four-helix bundle-like configuration featuring terminal beta-strands that can mediate higher order oligomerization. In solution, SPA17 forms both homodimers and tetramers, and displays a weak affinity for AKAP18. Quantitative approaches reveal that AKAP18 binding occurs at nanomolar affinity when SPA17 heterodimerizes with the ropporin-1-like D/D protein (ROPN1L). These findings expand the role of the D/D fold as a versatile protein interaction element that maintains the integrity of macromolecular architectures within organelles such as motile cilia.

Beyond PKA: Evolutionary and Structural Insights that Define a Docking and Dimerization Domain Superfamily.,Dahlin HR, Zheng N, Scott JD J Biol Chem. 2021 Jul 10:100927. doi: 10.1016/j.jbc.2021.100927. PMID:34256050^[1]

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