The Acyl-Proteome of Syntrophus aciditrophicus Reveals Metabolic Relationships in Benzoate Degradation

Mol Cell Proteomics. 2022 Apr;21(4):100215. doi: 10.1016/j.mcpro.2022.100215. Epub 2022 Feb 19.

Abstract

Syntrophus aciditrophicus is a model syntrophic bacterium that degrades fatty and aromatic acids into acetate, CO2, formate, and H2 that are utilized by methanogens and other hydrogen-consuming microbes. S. aciditrophicus benzoate degradation proceeds by a multistep pathway with many intermediate reactive acyl-coenzyme A species (RACS) that can potentially Nε-acylate lysine residues. Herein, we describe the identification and characterization of acyl-lysine modifications that correspond to RACS in the benzoate degradation pathway. The amounts of modified peptides are sufficient to analyze the post-translational modifications without antibody enrichment, enabling a range of acylations located, presumably, on the most extensively acylated proteins throughout the proteome to be studied. Seven types of acyl modifications were identified, six of which correspond directly to RACS that are intermediates in the benzoate degradation pathway including 3-hydroxypimeloylation, a modification first identified in this system. Indeed, benzoate-degrading enzymes are heavily represented among the acylated proteins. A total of 125 sites were identified in 60 proteins. Functional deacylase enzymes are present in the proteome, indicating a potential regulatory system/mechanism by which S. aciditrophicus modulates acylation. Uniquely, Nε-acyl-lysine RACS are highly abundant in these syntrophic bacteria, raising the compelling possibility that post-translational modifications modulate benzoate degradation in this and potentially other, syntrophic bacteria. Our results outline candidates for further study of how acylations impact syntrophic consortia.

Keywords: Syntrophus aciditrophicus; lysine acylation; sirtuins; syntrophs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacteria / metabolism
  • Benzoates / metabolism
  • Deltaproteobacteria* / metabolism
  • Lysine / metabolism
  • Proteome* / metabolism

Substances

  • Benzoates
  • Proteome
  • Lysine

Supplementary concepts

  • Syntrophus aciditrophicus