Download MendeleyStructural basis for catalytic activity of a silkworm Delta-class glutathione transferase
Yamamoto, K., Usuda, K., Kakuta, Y., Kimura, M., Higashiura, A., Nakagawa, A., Aso, Y., Suzuki, M.(2012) Biochim Biophys Acta 1820: 1469-1474
- PubMed: 22579926
- DOI: https://doi.org/10.1016/j.bbagen.2012.04.022
- Primary Citation of Related Structures:
3VK9 - PubMed Abstract:
Glutathione transferase (GST) catalyzes glutathione conjugation, a major detoxification pathway for xenobiotics and endogenous substances. Here, we determined the crystal structure of a Delta-class GST from Bombyx mori (bmGSTD) to examine its catalytic residues. The three-dimensional structure of bmGSTD was resolved by the molecular replacement method and refined to a resolution of 2.0Å. Structural alignment with a Delta-class GST of Anopheles gambiae indicated that bmGSTD contains 2 distinct domains (an N-terminal domain and a C-terminal domain) connected by a linker. The bound glutathione localized at the N-terminal domain. Putative catalytic residues were changed to alanine by site-directed mutagenesis, and the resulting mutants were characterized in terms of catalytic activity using glutathione and 1-chloro-2,4-dinitrobenzene, a synthetic substrate of GST. Kinetic analysis of bmGSTD mutants indicated that Ser11, Gln51, His52, Ser67, and Arg68 are important for enzyme function. These results provide structural insights into the catalysis of glutathione conjugation in B. mori by bmGSTD.
Organizational Affiliation:
Faculty of Agriculture, Kyushu University Graduate School, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. yamamok@agr.kyushu-u.ac.jp
