Author:
Pessoa João,Sárkány Zsuzsa,Ferreira-da-Silva Frederico,Martins Sónia,Almeida Maria R,Li Jianming,Damas Ana M
Abstract
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.
Publisher
Springer Science and Business Media LLC
Reference24 articles.
1. Nam KE, Li J: The Arabidopsis transthyretin-like protein is a potential substrate of Brassinosteroid Insensitive 1. The Plant Cell. 2004, 16: 2406-2417. 10.1105/tpc.104.023903.
2. Hennebry SC, Wright HM, Likic VA, Richardson SJ: Structural and functional evolution of transthyretin and transthyretin-like proteins. Proteins: Struct Func Bioinfo. 2006, 64: 1024-1045. 10.1002/prot.21033.
3. Power DM, Elias NP, Richardson SJ, Mendes J, Soares CM, Santos CRA: Evolution of the thyroid hormone-binding protein, transthyretin. Gen Comp Endocrinol. 2000, 119: 241-255. 10.1006/gcen.2000.7520.
4. Blake CC, Geisow MJ, Oatley SJ, Rérat B, Rérat C: Structure of prealbumin: secondary, tertiary and quaternary interactions determined by Fourier refinement at 1.8 Å. J Mol Biol. 1978, 121: 339-356. 10.1016/0022-2836(78)90368-6.
5. Wojtczak A, Cody V, Luft JR, Pangborn W: Structures of human transthyretin complexed with thyroxine at 2.0 Å resolution and 3',5'-dinitro-N-acetyl-L-thyroxine at 2.2 Å resolution. Acta Crystallogr. 1996, D52: 758-765.
Cited by
35 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献