Resonance assignment and secondary structure of the middle MA-3 domain and complete tandem MA-3 region of the tumour suppressor protein Pdcd4

摘要

Pdcd4 (Programmed Cell Death Protein 4) is a novel eukaryotic tumour suppressor protein, which is involved in the regulation of both transcription and translation (reviewed in Lankat-Buttgereit and Göke ). The protein contains two interacting MA-3 domains (MA-3M and MA-3C), which are linked by a short semi-flexible linker region (Waters et al. ; Suzuki et al. ). The MA-3 domains are involved in mediating specific protein–protein interactions with functional partners such as eIF4A (Yang et al. ). Here we report essentially complete backbone and side chain ¹⁵N, ¹³C and ¹H assignments for a construct composed of the middle MA-3 domain and subsequent linker region (MA-3M) and backbone assignments for the entire tandem MA-3 region of Pdcd4 (Pdcd4 MA-3M-C). Analysis of the backbone chemical shift data obtained indicates that Pdcd4 MA-3M contains eight helical regions corresponding to over 74% of the protein backbone and that Pdcd4 MA-3M-C contains fifteen helical regions (72%). Comparison of the position of these helical regions with those observed in the crystal structures suggests that the solution and crystal structures of both proteins are very similar.