Download MendeleyCrystal structures of SULT1A2 and SULT1A1 *3: insights into the substrate inhibition and the role of Tyr149 in SULT1A2.
Lu, J., Li, H., Zhang, J., Li, M., Liu, M.Y., An, X., Liu, M.C., Chang, W.(2010) Biochem Biophys Res Commun 396: 429-434
- PubMed: 20417180
- DOI: https://doi.org/10.1016/j.bbrc.2010.04.109
- Primary Citation of Related Structures:
1Z28, 1Z29 - PubMed Abstract:
The cytosolic sulfotransferases (SULTs) in vertebrates catalyze the sulfonation of endogenous thyroid/steroid hormones and catecholamine neurotransmitters, as well as a variety of xenobiotics, using 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as the sulfonate donor. In this study, we determined the structures of SULT1A2 and an allozyme of SULT1A1, SULT1A1 *3, bound with 3'-phosphoadenosine 5'-phosphate (PAP), at 2.4 and 2.3A resolution, respectively. The conformational differences between the two structures revealed a plastic substrate-binding pocket with two channels and a switch-like substrate selectivity residue Phe247, providing clearly a structural basis for the substrate inhibition. In SULT1A2, Tyr149 extends approximately 2.1A further to the inside of the substrate-binding pocket, compared with the corresponding His149 residue in SULT1A1 *3. Site-directed mutagenesis study showed that, compared with the wild-type SULT1A2, mutant Tyr149Phe SULT1A2 exhibited a 40 times higher K(m) and two times lower V(max) with p-nitrophenol as substrate. These latter data imply a significant role of Tyr149 in the catalytic mechanism of SULT1A2.
Organizational Affiliation:
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, People's Republic of China.
