2r82

Pyruvate phosphate dikinase (PPDK) triple mutant R219E/E271R/S262D adapts a second conformational state

spinqualitylabelsall models 2r82, resolution 3.60Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2r82 is a 1 chain structure with sequence from "bacteroides_symbiosus"_stevens_1956 "bacteroides symbiosus" stevens 1956. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: SO4 Related: 1kbl, 1kc7, 1dik Gene: ppdK ("Bacteroides symbiosus" Stevens 1956) Activity: Pyruvate, phosphate dikinase, with EC number 2.7.9.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PPDK_CLOSY] Catalyzes the reversible phosphorylation of pyruvate and phosphate. In E.histolytica and C.symbiosus, PPDK functions in the direction of ATP synthesis. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Pyruvate phosphate dikinase (PPDK) catalyzes the reversible conversion of phosphoenolpyruvate (PEP), AMP, and Pi to pyruvate and ATP. The enzyme contains two remotely located reaction centers: the nucleotide partial reaction takes place at the N-terminal domain, and the PEP/pyruvate partial reaction takes place at the C-terminal domain. A central domain, tethered to the N- and C-terminal domains by two closely associated linkers, contains a phosphorylatable histidine residue (His455). The molecular architecture suggests a swiveling domain mechanism that shuttles a phosphoryl group between the two reaction centers. In an early structure of PPDK from Clostridium symbiosum, the His445-containing domain (His domain) was positioned close to the nucleotide binding domain and did not contact the PEP/pyruvate-binding domain. Here, we present the crystal structure of a second conformational state of C. symbiosum PPDK with the His domain adjacent to the PEP-binding domain. The structure was obtained by producing a three-residue mutant protein (R219E/E271R/S262D) that introduces repulsion between the His and nucleotide-binding domains but preserves viable interactions with the PEP/pyruvate-binding domain. Accordingly, the mutant enzyme is competent in catalyzing the PEP/pyruvate half-reaction but the overall activity is abolished. The new structure confirms the swivel motion of the His domain. In addition, upon detachment from the His domain, the two nucleotide-binding subdomains undergo a hinge motion that opens the active-site cleft. A similar hinge motion is expected to accompany nucleotide binding (cleft closure) and release (cleft opening). A model of the coupled swivel and cleft opening motions was generated by interpolation between two end conformations, each with His455 positioned for phosphoryl group transfer from/to one of the substrates. The trajectory of the His domain avoids major clashes with the partner domains while preserving the association of the two linker segments. Swiveling domain mechanism in pyruvate phosphate dikinase.,Lim K, Read RJ, Chen CC, Tempczyk A, Wei M, Ye D, Wu C, Dunaway-Mariano D, Herzberg O Biochemistry. 2007 Dec 25;46(51):14845-53. Epub 2007 Dec 4. PMID:18052212 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Pyruvate phosphate dikinase

Proteopedia Page Contributors and Editors (what is this?)

OCA