研究・研究者
研究会・セミナー
| 演 題 | 「From structure to function: a guanylyltransferase HcgB involved in [Fe]-hydrogenase cofactor biosynthesis」 |
|---|---|
| 日 時 | 2012年11月13日(火) 16:00 より 18:00 まで |
| 講演者 | Seigo Shima, Ph.D. |
| 場 所 | 分子研 研究棟201号室 |
| 概 要 | Hydrogenases require for molecular hydrogen cleavage special metal centers, which is for [Fe] hydrogenase an iron guanylylpyridinol (FeGP) cofactor.[1,2] Its complex biosynthesis and the involved enzymes are insufficiently understood yet. A gene cluster (hcgA-G) mostly adjacent to the gene of [Fe] hydrogenase is, however, assumed to encode for enzymes of FeGP biosynthesis.[1] I will talk about the function and the structure-based mechanism of HcgB strongly inspired by its structure which was deposited by a structural genomic project. HcgB is structurally related to non-canonical nucleotide triphosphatase suggesting that HcgB is able to bind nucleotide triphosphate and therefore might catalyze the conjunction between pyridinol and GMP by a guanylyltransferase reaction proposed recently on the basis of retrosynthetic analysis.[3] This reaction could be successfully imitated using artificial pyridinol derivatives and GTP as substrates. The formed guanylylpyridinol products were identified by mass-spectrometric and NMR methods. Crystal structures of HcgB in complex with the 3,5-dimethyl-2,4-dihydroxypyridine-GMP product and the iron-free FeGP-cofactor confirmed the found function but also provided the molecular basis for product/substrate binding and the enzymatic mechanism.
[1] Thauer, R.K., Kaster, A.-K., Goenrich, M., Schick, M., Hiromoto, T. & Shima, S. (2010) Ann. Rev. Biochem. 79: 507-536. |
| その他 |
Group leader at Max-Planck-Institute for Terrestrial Microbiology |
| お問合せ先 | 古谷 祐詞 |
