1T6C

Structural characterization of the Ppx/GppA protein family: crystal structure of the Aquifex aeolicus family member

Summary for 1T6C

• Entry DOI: 10.2210/pdb1t6c/pdb
• Related: 1T6D
• Descriptor: exopolyphosphatase, IODIDE ION, CALCIUM ION, ... (6 entities in total)
• Functional Keywords: alpha/beta protein, actin-like fold, hydrolase
• Biological source: Aquifex aeolicus
• Total number of polymer chains: 1
• Total formula weight: 36813.72

Authors

Kristensen, O.,Laurberg, M.,Liljas, A.,Kastrup, J.S.,Gajhede, M. (deposition date: 2004-05-06, release date: 2004-08-03, Last modification date: 2024-04-03)

Primary citation

Kristensen, O.,Laurberg, M.,Liljas, A.,Kastrup, J.S.,Gajhede, M.
Structural characterization of the stringent response related exopolyphosphatase/guanosine pentaphosphate phosphohydrolase protein family
Biochemistry, 43:8894-8900, 2004

PubMed Abstract: Exopolyphosphatase/guanosine pentaphosphate phosphohydrolase (PPX/GPPA) enzymes play central roles in the bacterial stringent response induced by starvation. The high-resolution crystal structure of the putative Aquifex aeolicus PPX/GPPA phosphatase from the actin-like ATPase domain superfamily has been determined, providing the first insights to features of the common catalytic core of the PPX/GPPA family. The protein has a two-domain structure with an active site located in the interdomain cleft. Two crystal forms were investigated (type I and II) at resolutions of 1.53 and 2.15 A, respectively. This revealed a structural flexibility that has previously been described as a "butterfly-like" cleft opening around the active site in other actin-like superfamily proteins. A calcium ion is observed at the center of this region in type I crystals, substantiating that PPX/GPPA enzymes use metal ions for catalysis. Structural analysis suggests that nucleotides bind at a similar position to that seen in other members of the superfamily.

PubMed: 15248747
DOI: 10.1021/bi049083c

Experimental method

X-RAY DIFFRACTION (1.53 Å)