Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Functional characterization of Arabidopsis thaliana transthyretin-like protein | Pessoa et al. BMC Plant Biology 2010 10 30 http 1471-2229 10 30 BMC Plant Biology RESEARCH ARTICLE Open Access Functional characterization of Arabidopsis thaliana transthyretin-like protein 1 J - I 1 1 1 3 João Pessoa Zsuzsa Sárkány Frederico Ferreira-da-Silva Sónia Martins Maria R Almeida Jianming Li Ana M Damas1 2 Abstract Background Arabidopsis thaliana transthyretin-like TTL protein is a potential substrate in the brassinosteroid signalling cascade having a role that moderates plant growth. Moreover sequence homology revealed two sequence domains similar to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline OHCU decarboxylase N-terminal domain and 5-hydroxyisourate 5-HIU hydrolase C-terminal domain . TTL is a member of the transthyretin-related protein family TRP which comprises a number of proteins with sequence homology to transthyretin TTR and the characteristic C-terminal sequence motif Tyr-Arg-Gly-Ser. TRPs are single domain proteins that form tetrameric structures with 5-HIU hydrolase activity. Experimental evidence is fundamental for knowing if TTL is a tetrameric protein formed by the association of the 5-HIU hydrolase domains and in this case if the structural arrangement allows for OHCU decarboxylase activity. This work reports about the biochemical and functional characterization of TTL. Results The TTL gene was cloned and the protein expressed and purified for biochemical and functional characterization. The results show that TTL is composed of four subunits with a moderately elongated shape. We also found evidence for 5-HIU hydrolase and OHCU decarboxylase activities in vitro in the full-length protein. Conclusions The Arabidopsis thaliana transthyretin-like TTL protein is a tetrameric bifunctional enzyme since it has 5-HIU hydrolase and OHCU decarboxylase activities which were simultaneously observed in vitro. Background The Arabidopsis thaliana transthyretin-like protein TTL was first identified as a potential substrate of .
