7QAQ

Crystal structure of a cyclodipeptide synthase from Parcubacteria bacterium RAAC4_OD1_1, E174A mutant

7QAQ の概要

• エントリーDOI: 10.2210/pdb7qaq/pdb
• 分子名称: Cyclodipeptide synthase (2 entities in total)
• 機能のキーワード: cyclodipeptide synthase, ligase
• 由来する生物種: Parcubacteria bacterium RAAC4_OD1_1
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 27276.48

構造登録者

Sutherland, E.,Harding, C.J.,Czekster, C.M. (登録日: 2021-11-17, 公開日: 2022-09-28, 最終更新日: 2024-01-31)

主引用文献

Sutherland, E.,Harding, C.J.,Czekster, C.M.
Active site remodelling of a cyclodipeptide synthase redefines substrate scope.
Commun Chem, 5:101-101, 2022

PubMed Abstract: Cyclodipeptide synthases (CDPSs) generate a wide range of cyclic dipeptides using aminoacylated tRNAs as substrates. Histidine-containing cyclic dipeptides have important biological activities as anticancer and neuroprotective molecules. Out of the 120 experimentally validated CDPS members, only two are known to accept histidine as a substrate yielding cyclo(His-Phe) and cyclo(His-Pro) as products. It is not fully understood how CDPSs select their substrates, and we must rely on bioprospecting to find new enzymes and novel bioactive cyclic dipeptides. Here, we developed an in vitro system to generate an extensive library of molecules using canonical and non-canonical amino acids as substrates, expanding the chemical space of histidine-containing cyclic dipeptide analogues. To investigate substrate selection we determined the structure of a cyclo(His-Pro)-producing CDPS. Three consecutive generations harbouring single, double and triple residue substitutions elucidated the histidine selection mechanism. Moreover, substrate selection was redefined, yielding enzyme variants that became capable of utilising phenylalanine and leucine. Our work successfully engineered a CDPS to yield different products, paving the way to direct the promiscuity of these enzymes to produce molecules of our choosing.

PubMed: 36518199
DOI: 10.1038/s42004-022-00715-2

実験手法

X-RAY DIFFRACTION (2.4 Å)