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Structure of the two-domain hexameric APS kinase from Thiobacillus denitrificans: structural basis for the absence of ATP sulfurylase activity.
- Source :
-
Acta Crystallographica: Section D (Wiley-Blackwell) . Oct2009, Vol. 65 Issue 10, p1021-1031. 11p. 7 Diagrams, 1 Chart. - Publication Year :
- 2009
-
Abstract
- The Tbd_0210 gene of the chemolithotrophic bacterium Thiobacillus denitrificans is annotated to encode a 60.5 kDa bifunctional enzyme with ATP sulfurylase and APS kinase activity. This putative bifunctional enzyme was cloned, expressed and structurally characterized. The 2.95 Å resolution X-ray crystal structure reported here revealed a hexameric assembly with D symmetry. Each subunit contains a large N-terminal sulfurylase-like domain and a C-terminal APS kinase domain reminiscent of the two-domain fungal ATP sulfurylases of Penicillium chrysogenum and Saccharomyces cerevisiae, which also exhibit a hexameric assembly. However, the T. denitrificans enzyme exhibits numerous structural and sequence differences in the N-terminal domain that render it inactive with respect to ATP sulfurylase activity. Surprisingly, the C-terminal domain does indeed display APS kinase activity, indicating that this gene product is a true APS kinase. Therefore, these results provide the first structural insights into a unique hexameric APS kinase that contains a nonfunctional ATP sulfurylase-like domain of unknown function. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 09074449
- Volume :
- 65
- Issue :
- 10
- Database :
- Academic Search Index
- Journal :
- Acta Crystallographica: Section D (Wiley-Blackwell)
- Publication Type :
- Academic Journal
- Accession number :
- 44961213
- Full Text :
- https://doi.org/10.1107/S0907444909026547