4JD0
Structure of the inositol-1-phosphate CTP transferase from T. maritima.
Summary for 4JD0
| Entry DOI | 10.2210/pdb4jd0/pdb |
| Descriptor | Nucleotidyl transferase, arsenoribose, CHLORIDE ION, ... (7 entities in total) |
| Functional Keywords | alpha/beta motif of sugar nucleotidyltransferase, transferase |
| Biological source | Thermotoga maritima |
| Total number of polymer chains | 1 |
| Total formula weight | 29354.14 |
| Authors | Stec, B. (deposition date: 2013-02-22, release date: 2013-09-18, Last modification date: 2024-11-27) |
| Primary citation | Kurnasov, O.V.,Luk, H.J.,Roberts, M.F.,Stec, B. Structure of the inositol-1-phosphate cytidylyltransferase from Thermotoga maritima. Acta Crystallogr.,Sect.D, 69:1808-1817, 2013 Cited by PubMed Abstract: The unique steps in the synthesis of an unusual osmolyte in hyperthermophiles, di-myo-inositol-1,1'-phosphate (DIP), involve the production of CDP-inositol and its condensation with an inositol-1-phosphate molecule to form phosphorylated DIP. While many organisms fuse both activities into a single enzyme, the two are separate in Thermotoga maritima. The crystal structure of the T. maritima inositol-1-phosphate cytidylyltransferase, which as a soluble protein may transiently associate with its membrane-embedded partner phospho-DIP synthase (P-DIPS), has now been obtained. The structure shows a conserved motif of sugar nucleotide transferases (COG1213) with a structurally reinforced C-terminal Cys bonded to the core of the protein. A bound arsenosugar identifies the location of the active site for inositol 1-phosphate. Based on homologous structures from several species and the identification of the crucial conserved aspartate residue, a catalytic mechanism for this enzyme is proposed as well as a mode for its association with P-DIPS. This structure imposes constraints on the mode of association, communication and temperature activation of two separate enzymes in T. maritima. For the first time, a working model for the membrane-bound P-DIPS unit has been constructed. This sheds light on the functioning of the phosphatidylserine and phosphatidylinositol synthases involved in many physiological processes that are homologous to P-DIPS. This work provides fresh insights into the synthesis of the unusual thermoprotective compound DIP in hyperthermophiles. PubMed: 23999304DOI: 10.1107/S0907444913015278 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.8 Å) |
Structure validation
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