Solution structure of a ubiquitin-like protein from Trypanosoma brucei.

Ubiquitin-like proteins, similar to ubiquitin, can either exist freely or be covalently attached to other proteins via an enzymatic cascade. The ubiquitin-like proteins play roles in multiple biological processes including transcription, stress responses, DNA repair and so on. In this study, a novel ubiquitin-like protein (TbUbl11) was identified in Trypanosoma brucei. The solution structure of TbUbl11 was solved by NMR spectroscopy. TbUbl11 adopts a conserved β-grasp fold composed by a five-stranded β-sheet curling around a central α-helix, similar to other ubiquitin-like proteins. Meanwhile, some differences between TbUbl11 and other ubiquitin-like proteins were also identified. Additionally, we revealed that TbUbl11 is located in the whole cell body of procyclic-form T. brucei.