ubiquitin-like (Ubl) domain found in sulfur carrier protein ThiS
ThiS, also termed Thiamine biosynthesis protein (ThiaminS), is a sulfur carrier protein involved in thiamin biosynthesis in prokaryotes. It has the beta-grasp ubiquitin-like (Ubl) fold with low sequence similarity to ubiquitin (Ub), and is activated in an ATP-dependent manner by sulfurtransferases, similar to the activation mechanism of Ub-activating enzyme E1. ThiS has common evolutionary origin with Ub-related protein modifiers in eukaryotes, a beta-grasp fold as Ub, and is closely related to proteins MoaD and Urm1.
Structure:1ZUD; Escherichia coli ThiS interacts with thiazole biosynthesis adenylyltransferase ThiF, contacts at 4A
Comment:ThiS is a small protein that structurally resembles ubiquitin and the molybdopterin biosynthetic protein MoaD; ThiF has distinct sequence and structural similarity to the ubiquitin activating enzyme E1 and the molybdopterin biosynthetic protein MoeB; ThiS and ThiF are bacterial proteins involved in the synthesis of the thiazole moiety of thiamin