3lkk

Crystal structure of the isopentenyl phosphate kinase substrate complex

spinqualitylabelsall models 3lkk, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3lkk is a 2 chain structure with sequence from Theac. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ATP, IP8 Gene: Ta0103 (THEAC) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 Isoprenoid compounds are ubiquitous in nature, participating in important biological phenomena such as signal transduction, aerobic cellular respiration, photosynthesis, insect communication, and many others. They are derived from the 5-carbon isoprenoid substrates isopentenyl diphosphate (IPP) and its isomer dimethylallyl diphosphate (DMAPP). In Archaea and Eukarya, these building blocks are synthesized via the mevalonate pathway. However, the genes required to convert mevalonate phosphate (MP) to IPP are missing in several species of Archaea. An enzyme with isopentenyl phosphate kinase (IPK) activity was recently discovered in Methanocaldococcus jannaschii (MJ), suggesting a departure from the classical sequence of converting MP to IPP. We have determined the high-resolution crystal structures of isopentenyl phosphate kinases in complex with both substrates and products from Thermoplasma acidophilum (THA), as well as the IPK from Methanothermobacter thermautotrophicus (MTH), by means of single-wavelength anomalous diffraction (SAD) and molecular replacement. A histidine residue (His50) in THA IPK makes a hydrogen bond with the terminal phosphates of IP and IPP, poising these molecules for phosphoryl transfer through an in-line geometry. Moreover, a lysine residue (Lys14) makes hydrogen bonds with nonbridging oxygen atoms at P(alpha) and P(gamma) and with the P(beta)-P(gamma) bridging oxygen atom in ATP. These interactions suggest a transition-state-stabilizing role for this residue. Lys14 is a part of a newly discovered "lysine triangle" catalytic motif in IPKs that also includes Lys5 and Lys205. Moreover, His50, Lys5, Lys14, and Lys205 are conserved in all IPKs and can therefore serve as fingerprints for identifying new homologues. X-ray structures of isopentenyl phosphate kinase.,Mabanglo MF, Schubert HL, Chen M, Hill CP, Poulter CD ACS Chem Biol. 2010 May 21;5(5):517-27. PMID:20402538 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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