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Ubiquitination is one of the most prevalent forms of post-translational modifications that are important for regulating many cellular processes in eukaryotes. Deubiquitinases are proteases that hydrolyze the isopeptide or peptide bonds formed between ubiquitin and the target proteins or within a polyubiquitin chain. Deubiquitinase A (DUBA) is a deubiquitinase known to be a negative regulator of innate immune responses in humans by suppressing production of type I interferons (INF-I). Excess INF-I production has been associated with autoimmune diseases. Phosphorylation of a single serine residue at position 177 is essential for the protease activity of DUBA. The structural and mechanistic basis of DUBA activation by phosphorylation and substrate specificity is not well understood. Here, we report the backbone resonance assignments of the isoform 2 of DUBA in both non-phosphorylated and phosphorylated forms. The reported assignments form the basis for future NMR studies on the structural and dynamical properties of both active and inactive forms of DUBA.

Lignin, a major constituent of plant call wall, is a phenolic heteropolymer. It plays a major role in the development of plants and their defense mechanism against pathogens. Therefore Lignin biosynthesis is one of the critical metabolic pathways. In lignin biosynthesis, the Cinnamoyl CoA reductase is a key enzyme which catalyzes the first step in the pathway. Cinnamoyl CoA reductase provides the substrates which represent the main transitional molecules of lignin biosynthesis pathway, exhibits a high in vitro kinetic preference for feruloyl CoA. In present study, the three-dimensional model of cinnamoyl CoA reductase was constructed based on the crystal structure of Grape Dihydroflavonol 4-Reductase. Furthermore, the docking studies were performed to understand the substrate interactions to the active site of CCR. It showed that residues ARG51, ASN52, ASP54 and ASN58 were involved in substrate binding. We also suggest that residue ARG51 in CCR is the determinant residue in competitive inhibition of other substrates. This structural and docking information have prospective implications to understand the mechanism of CCR enzymatic reaction with feruloyl CoA, however the approach will be applicable in prediction of substrates and engineering 3D structures of other enzymes as well.