Crystal structure of Thermobifida fusca cis-prenyltransferase reveals the dynamic nature of its RXG motif-mediated inter-subunit interactions critical for its catalytic activity

Hirofumi Kurokawa, Takanori Ambo, Seiji Takahashi, Tanetoshi Koyama

Research output: Contribution to journalArticlepeer-review

Abstract

cis-Prenyltransferases (cis-PTs) catalyze consecutive condensations of isopentenyl diphosphate to an allylic diphosphate acceptor to produce a linear polyprenyl diphosphate of designated length. Dimer formation is a prerequisite for cis-PTs to catalyze all cis-prenyl condensation reactions. The structure-function relationship of a conserved C-terminal RXG motif in cis-PTs that forms inter-subunit interactions and has a role in catalytic activity has attracted much attention. Here, we solved the crystal structure of a medium-chain cis-PT from Thermobifida fusca that produces dodecaprenyl diphosphate as a polyprenoid glycan carrier for cell wall synthesis. The structure revealed a characteristic dimeric architecture of cis-PTs in which a rigidified RXG motif of one monomer formed inter-subunit hydrogen bonds with the catalytic site of the other monomer, while the RXG motif of the latter remained flexible. Careful analyses suggested the existence of a possible long-range negative cooperativity between the two catalytic sites on the two monomeric subunits that allowed the binding of one subunit to stabilize the formation of the enzyme-substrate ternary complex and facilitated the release of Mg-PPi and subsequent intra-molecular translocation at the counter subunit so that the condensation reaction could occur in consecutive cycles. The current structure reveals the dynamic nature of the RXG motif and provides a rationale for pursuing further investigations to elucidate the inter-subunit cooperativity of cis-PTs.

Original languageEnglish
Pages (from-to)459-465
Number of pages7
JournalBiochemical and biophysical research communications
Volume532
Issue number3
DOIs
Publication statusPublished - 2020 Nov 12

Keywords

  • Isoprenoid
  • Negative cooperativity
  • RXG motif
  • X-ray crystallography
  • cis-Prenyltransferase

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Crystal structure of Thermobifida fusca cis-prenyltransferase reveals the dynamic nature of its RXG motif-mediated inter-subunit interactions critical for its catalytic activity'. Together they form a unique fingerprint.

Cite this