2XHG

Crystal Structure of the Epimerization Domain from the Initiation Module of Tyrocidine Biosynthesis

2XHG の概要

• エントリーDOI: 10.2210/pdb2xhg/pdb
• 分子名称: TYROCIDINE SYNTHETASE A, GLYCEROL, SODIUM ION, ... (4 entities in total)
• 機能のキーワード: isomerase, nonribosomal peptide synthesis, cofactor-independent epimerization
• 由来する生物種: BREVIBACILLUS BREVIS
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 53460.79

構造登録者

Samel, S.-A.,Heine, A.,Marahiel, M.A.,Essen, L.-O. (登録日: 2010-06-15, 公開日: 2011-07-06, 最終更新日: 2024-05-08)

主引用文献

Samel, S.-A.,Czodrowski, P.,Essen, L.-O.
Structure of the Epimerization Domain of Tyrocidine Synthetase A
Acta Crystallogr.,Sect.D, 70:1442-, 2014

PubMed Abstract: Tyrocidine, a macrocyclic decapeptide from Bacillus brevis, is nonribosomally assembled by a set of multimodular peptide synthetases, which condense two D-amino acids and eight L-amino acids to produce this membrane-disturbing antibiotic. D-Phenylalanine, the first amino acid incorporated into tyrocidine, is catalytically derived from enzyme-bound L-Phe by the C-terminal epimerization (E) domain of tyrocidine synthetase A (TycA). The 1.5 Å resolution structure of the cofactor-independent TycA E domain reveals an intimate relationship to the condensation (C) domains of peptide synthetases. In contrast to the latter, the TycA E domain uses an enlarged bridge region to plug the active-site canyon from the acceptor side, whereas at the donor side a latch-like floor loop is suitably extended to accommodate the αIII helix of the preceding peptide-carrier domain. Additionally, E domains exclusively harbour a conserved glutamate residue, Glu882, that is opposite the active-site residue His743. This active-site topology implies Glu882 as a candidate acid-base catalyst, whereas His743 stabilizes in the protonated state a transient enolate intermediate of the L↔D isomerization.

PubMed: 24816112
DOI: 10.1107/S1399004714004398

実験手法

X-RAY DIFFRACTION (1.5 Å)