4JD0

Structure of the inositol-1-phosphate CTP transferase from T. maritima.

4JD0 の概要

• エントリーDOI: 10.2210/pdb4jd0/pdb
• 分子名称: Nucleotidyl transferase, arsenoribose, CHLORIDE ION, ... (7 entities in total)
• 機能のキーワード: alpha/beta motif of sugar nucleotidyltransferase, transferase
• 由来する生物種: Thermotoga maritima
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 29354.14

構造登録者

Stec, B. (登録日: 2013-02-22, 公開日: 2013-09-18, 最終更新日: 2024-11-27)

主引用文献

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

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: 23999304
DOI: 10.1107/S0907444913015278

実験手法

X-RAY DIFFRACTION (1.8 Å)