Biochemical Investigation of Rv3404c from Mycobacterium tuberculosis

Biochemistry. 2017 Jul 25;56(29):3818-3825. doi: 10.1021/acs.biochem.7b00506. Epub 2017 Jul 14.

Abstract

The causative agent of tuberculosis, Mycobacterium tuberculosis, is a bacterium with a complex cell wall and a complicated life cycle. The genome of M. tuberculosis contains well over 4000 genes thought to encode proteins. One of these codes for a putative enzyme referred to as Rv3404c, which has attracted research attention as a potential virulence factor for over 12 years. Here we demonstrate that Rv3404c functions as a sugar N-formyltransferase that converts dTDP-4-amino-4,6-dideoxyglucose into dTDP-4-formamido-4,6-dideoxyglucose using N10-formyltetrahydrofolate as the carbon source. Kinetic analyses demonstrate that Rv3404c displays a significant catalytic efficiency of 1.1 × 104 M-1 s-1. In addition, we report the X-ray structure of a ternary complex of Rv3404c solved in the presence of N5-formyltetrahydrofolate and dTDP-4-amino-4,6-dideoxyglucose. The final model of Rv3404c was refined to an overall R-factor of 16.8% at 1.6 Å resolution. The results described herein are especially intriguing given that there have been no published reports of N-formylated sugars associated with M. tuberculosis. The data thus provide a new avenue of research into this fascinating, yet deadly, organism that apparently has been associated with human infection since ancient times.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism
  • Catalysis
  • Crystallography, X-Ray
  • Deoxy Sugars / chemistry
  • Deoxy Sugars / metabolism
  • Formyltetrahydrofolates / chemistry
  • Formyltetrahydrofolates / metabolism
  • Hydroxymethyl and Formyl Transferases / chemistry*
  • Hydroxymethyl and Formyl Transferases / metabolism
  • Kinetics
  • Models, Molecular*
  • Mycobacterium tuberculosis / enzymology*
  • Mycobacterium tuberculosis / pathogenicity
  • Thymine Nucleotides / chemistry
  • Thymine Nucleotides / metabolism
  • Virulence Factors / chemistry*
  • Virulence Factors / metabolism

Substances

  • Bacterial Proteins
  • Deoxy Sugars
  • Formyltetrahydrofolates
  • Thymine Nucleotides
  • Virulence Factors
  • dTDP-4-amino-4,6-dideoxy-glucose
  • Hydroxymethyl and Formyl Transferases