3CR8

Hexameric APS kinase from Thiobacillus denitrificans

Summary for 3CR8

• Entry DOI: 10.2210/pdb3cr8/pdb
• Descriptor: Sulfate adenylyltransferase, adenylylsulfate kinase (2 entities in total)
• Functional Keywords: aps kinase, adenylylsulfate kinase, transferase, sulfate metabolism, nucleotide 2 kinase, nucleotidyltransferase
• Biological source: Thiobacillus denitrificans (strain ATCC 25259)
• Total number of polymer chains: 3
• Total formula weight: 184914.96

Authors

Gay, S.C.,Segel, I.H.,Fisher, A.J. (deposition date: 2008-04-04, release date: 2009-02-17, Last modification date: 2023-08-30)

Primary citation

Gay, S.C.,Segel, I.H.,Fisher, A.J.
Structure of the two-domain hexameric APS kinase from Thiobacillus denitrificans: structural basis for the absence of ATP sulfurylase activity.
Acta Crystallogr.,Sect.D, 65:1021-1031, 2009

PubMed 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 A resolution X-ray crystal structure reported here revealed a hexameric assembly with D(3) 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.

PubMed: 19770499
DOI: 10.1107/S0907444909026547

Experimental method

X-RAY DIFFRACTION (2.95 Å)