1QHY

CHLORAMPHENICOL PHOSPHOTRANSFERASE FROM STREPTOMYCES VENEZUELAE IN COMPLEX WITH ATPGAMMAS AND CHLORAMPHENICOL

1QHY の概要

• エントリーDOI: 10.2210/pdb1qhy/pdb
• 関連するPDBエントリー: 1QHN 1QHS 1QHX
• 分子名称: CHLORAMPHENICOL PHOSPHOTRANSFERASE, SULFATE ION, MAGNESIUM ION, ... (6 entities in total)
• 機能のキーワード: kinase, antibiotic resistance, phosphorylation, mononucleotide binding fold, transferase
• 由来する生物種: Streptomyces venezuelae
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 20124.24

構造登録者

Izard, T. (登録日: 1999-06-01, 公開日: 2000-06-07, 最終更新日: 2023-08-02)

主引用文献

Izard, T.,Ellis, J.
The Crystal Structures of Chloramphenicol Phosphotransferase Reveal a Novel Inactivation Mechanism
Embo J., 19:2690-2700, 2000

PubMed Abstract: Chloramphenicol (Cm), produced by the soil bacterium Streptomyces venezuelae, is an inhibitor of bacterial ribosomal peptidyltransferase activity. The Cm-producing streptomycete modifies the primary (C-3) hydroxyl of the antibiotic by a novel Cm-inactivating enzyme, chloramphenicol 3-O-phosphotransferase (CPT). Here we describe the crystal structures of CPT in the absence and presence of bound substrates. The enzyme is dimeric in a sulfate-free solution and tetramerization is induced by ammonium sulfate, the crystallization precipitant. The tetrameric quaternary structure exhibits crystallographic 222 symmetry and has ATP binding pockets located at a crystallographic 2-fold axis. Steric hindrance allows only one ATP to bind per dimer within the tetramer. In addition to active site binding by Cm, an electron-dense feature resembling the enzyme's product is found at the other subunit interface. The structures of CPT suggest that an aspartate acts as a general base to accept a proton from the 3-hydroxyl of Cm, concurrent with nucleophilic attack of the resulting oxyanion on the gamma-phosphate of ATP. Comparison between liganded and substrate-free CPT structures highlights side chain movements of the active site's Arg136 guanidinium group of >9 A upon substrate binding.

PubMed: 10835366
DOI: 10.1093/emboj/19.1.1

実験手法

X-RAY DIFFRACTION (2.6 Å)