1XKV

Crystal Structure Of ATP-Dependent Phosphoenolpyruvate Carboxykinase From Thermus thermophilus HB8

Replaces:  1WG9

Summary for 1XKV

• Entry DOI: 10.2210/pdb1xkv/pdb
• Related: 1J3B
• Descriptor: ATP-dependent phosphoenolpyruvate carboxykinase, CALCIUM ION, PHOSPHATE ION, ... (6 entities in total)
• Functional Keywords: phosphoenolpyruvate carboxykinase, adenosine triphosphate, thermus thermophilus, riken structural genomics/proteomics initiative, rsgi, structural genomics, lyase
• Biological source: Thermus thermophilus
• Cellular location: Cytoplasm (By similarity): Q5SLL5
• Total number of polymer chains: 2
• Total formula weight: 120115.73

Authors

Sugahara, M.,Kunishima, N.,RIKEN Structural Genomics/Proteomics Initiative (RSGI) (deposition date: 2004-09-29, release date: 2005-10-11, Last modification date: 2023-10-25)

Primary citation

Sugahara, M.,Ohshima, N.,Ukita, Y.,Sugahara, M.,Kunishima, N.
Structure of ATP-dependent phosphoenolpyruvate carboxykinase from Thermus thermophilus HB8 showing the structural basis of induced fit and thermostability.
Acta Crystallogr.,Sect.D, 61:1500-1507, 2005

PubMed Abstract: In order to understand the induced fit and the thermostabilization mechanisms of ATP-dependent phosphoenolpyruvate carboxykinase, the crystal structure of the enzyme from the extreme thermophile Thermus thermophilus HB8 (TtPEPCK) was determined and compared with those of orthologues of known structure from two mesophilic organisms. The protomer structures in these orthologues, which exhibit open/closed interdomain conformations, are similar. Isomorphous crystals of unliganded and ATP-bound TtPEPCK were obtained. The asymmetric units of both crystal forms contain two protomers A and B with closed and open conformations, respectively. ATP was only observed in the interdomain cleft of the closed protomer, suggesting that the induced fit of TtPEPCK agrees with the so-called ;conformational selection' mechanism where ligand binding is not essential for domain closure although its binding leads to the stabilization of the closed state. A bound calcium observed in the N-terminal domain of TtPEPCK probably contributes to the thermal stability. A combination of hydrophobic effects, ion pairs and entropic effects might also contribute to the thermostability of TtPEPCK.

PubMed: 16239727
DOI: 10.1107/S090744490502651X

Experimental method

X-RAY DIFFRACTION (2.2 Å)