| Autor: |
Takahashi, Hitomi, Inagaki, Eiji, Fujimoto, Yayoi, Kuroishi, Chizu, Nodake, Yuichi, Nakamura, Yuki, Arisaka, Fumio, Yutani, Katsuhide, Kuramitsu, Seiki, Yokoyama, Shigeyuki, Yamamoto, Masaki, Miyano, Masashi, Tahirov, Tahir H. |
| Předmět: |
|
| Zdroj: |
Acta Crystallographica: Section D (Wiley-Blackwell); Jan2004, Vol. 60 Issue 1, p97-104, 8p |
| Abstrakt: |
Phosphopantetheine adenylyltransferase (PPAT) is an essential enzyme in bacteria that catalyzes the rate-limiting step in coenzyme A (CoA) biosynthesis by transferring an adenylyl group from ATP to 4'- thosphopantetheine (Ppant), yielding 3'-dephospho-CoA (dPCoA). The crystal structure of PPAT from Thermus thermophiIus HB38 (Ti PPAT) complexed with Ppant has been determined by the molecular-replacement method at 15 A resolution. The overall fold of the enzyme is almost the same as that of Escherichia coil PPAT. a hexamer having point group 32. The asymmetric unit of Tt PPAT contains a monomer and the crystallographic triad and dyad coincide with the threefold and twofold axes of the hexamer. respectively. Most of the important atoms surrounding the active site in E. coil PPAT are conserved in Ti PPAT, indicating similarities in their substrate binding and enzymatic reaction. The notable difference between E. coli PPAT and Ti P.PAT is the simultaneous substrate recognition by all six subunits of Ti PPAT compared with substrate recognition by only three subunits in E. coil PPAT. Comparative analysis also revealed that the higher stability of Ti PPAT arises from stabilization of each subunit by hydrophobic effects, hydrogen bonds and entropic effects. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
