Taxonomic distribution of proteins containing DWNN domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing DWNN domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

DWNN, a novel ubiquitin-like domain, implicates RBBP6 in mRNA processing andubiquitin-like pathways.

Pugh DJ, Ab E, Faro A, Lutya PT, Hoffmann E, Rees DJ
BMC Struct Biol. 2006; 6: 1-1

BACKGROUND: RBBP6 is a 250 kDa splicing-associated protein that has beenidentified as an E3 ligase due to the presence of a RING finger domain. In humansand mice it interacts with both p53 and Rb, and plays a role in the induction of apoptosis and regulation of the cell cycle. RBBP6 has recently been shown to behighly up-regulated in oesophageal cancer, and to be a promising target forimmunotherapy against the disease. RESULTS: We show here using heteronuclear NMR that the N-terminal 81 amino acids of RBBP6 constitute a novel ubiquitin-likedomain, which we have called the DWNN domain. The domain lacks conservedequivalents of K48 and K63, although the equivalents of K6 and K29 are highly,although not absolutely, conserved. The di-glycine motif that is characteristicof proteins involved in ubiquitination is found in the human and mouse form ofthe domain, although it is not present in all organisms. It forms part of athree-domain form of RBBP6 containing the DWNN domain, a zinc knuckle and a RING finger domain, which is found in all eukaryotic genomes so far examined, in themajority of cases at single copy number. The domain is also independentlyexpressed in vertebrates as a single domain protein. CONCLUSION: DWNN is a novel ubiquitin-like domain found only at the N-terminus of the RBBP6 family ofsplicing-associated proteins. The ubiquitin-like structure of the domain greatly increases the likelihood that RBBP6 functions through some form of ubiquitin-likemodification. Furthermore, the fact that the DWNN domain is independentlyexpressed in higher vertebrates leads us to propose that the domain may itselffunction as a novel ubiquitin-like modifier of other proteins.