Vol.:(0123456789) 1 3 Biomol NMR Assign DOI 10.1007/s12104-017-9772-5 ARTICLE Backbone 1 H, 13 C and  15 N chemical shift assignment of full-length human uracil DNA glycosylase UNG2 Edith Buchinger 1  · Siv Å. Wiik 1,3  · Anna Kusnierczyk 2  · Renana Rabe 2  · Per. A. Aas 2  · Bodil Kavli 2  · Geir Slupphaug 2  · Finn L. Aachmann 1   Received: 7 July 2017 / Accepted: 28 August 2017 © Springer Science+Business Media B.V. 2017 Biological context The nuclear human uracil-DNA glycosylase UNG2 is the major enzyme for removal of both misincorporated uracil (U:A) and miscoding deaminated cytosine (U:G) in the genome (Kavli et al. 2002). In addition, UNG2 is essen- tial in adaptive immunity where it works together with the deaminase AID in affinity maturation of antibodies (PMID:17116429). The highly conserved catalytic C-ter- minal core domain of UNG (C-UNG2, residues 93–313) has previously been crystallized both as native protein and in a complex with DNA (Mol et al. 1995; Slupphaug et al. 1996). The crystal structures display a compact globular domain. This is in contrast to the less conserved N-terminal region that is predicted to be mainly unstructured (Kavli et al. 2002) and is not necessary for enzymatic activity. However, there are noticeable changes in biochemical properties of full- length UNG2 that are not displayed by the catalytic domain alone. These include a strong single-strand DNA prefer- ence of full-length UNG2 in the presence of physiological concentrations of Mg 2+ (Kavli et al. 2002). The N-terminal region of UNG2 contains a nuclear localization signal and PCNA (proliferating cell nuclear antigen) interacting motif (PIP-box) (Otterlei et al. 1999) that targets the repair enzyme to the nucleus and replication foci, respectively. Moreover, this region contains three cell-cycle regulated phosphoryla- tion sites (Hagen et al. 2008). The stepwise phosphorylation of S23, T60 and S64 through the cell cycle is apparently catalyzed by cyclin-dependent kinases. In replicating cells, PCNA and replication protein A (RPA) associate with the N-terminal region of UNG2 at two specifc motifs (Mer et al. 2000; Otterlei et al. 1999). Binding to PCNA indicate the important role of UNG2 in rapid postreplicative removal of misincorporated dUMP at the replication fork (Otterlei et al. 1999) whereas binding to RPA might direct UNG2 to the Abstract Human uracil N-glycosylase isoform 2—UNG2 consists of an N-terminal intrinsically disordered regula- tory domain (UNG2 residues 1–92, 9.3 kDa) and a C-ter- minal structured catalytic domain (UNG2 residues 93–313, 25.1 kDa). Here, we report the backbone 1 H, 13 C, and 15 N chemical shift assignment as well as secondary structure analysis of the N-and C-terminal domains of UNG2 repre- senting the full-length UNG2 protein. Keywords Uracil-DNA glycosylase · Uracil N-glycosylase isoform 2 · UNG2 · DNA repair · Intrinsically disordered domain Abbreviations SLIC Sequence- and ligation independent cloning UNG2 Uracil N-glycosylase isoform 2 N-UNG2 Residues 1–92 of UNG2 AA Amino acid PCNA Proliferating cell nuclear antigen RPA Replication protein A CBD Chitin binding domain C-UNG2 Residues 93–313 of UNG2-G93C * Finn L. Aachmann fnn.l.aachmann@ntnu.no 1 NOBIPOL, Department of Biotechnology, NTNU- Norwegian University of Science and Technology, 7491 Trondheim, Norway 2 Department of Cancer Research and Molecular Medicine, NTNU - Norwegian University of Science and Technology, 7491 Trondheim, Norway 3 Present Address: Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway