Related Experiment Video
Updated: May 17, 2026

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria
Published on: September 16, 2013
Tyrosine sulfation in a Gram-negative bacterium
Sang-Wook Han1, Sang-Won Lee, Ofir Bahar
1Department of Plant Pathology and the Genome Center, University of California, One Shields Ave, Davis, California 95616, USA.
Scientists discovered tyrosine sulfation, a protein modification, in bacteria for the first time. The RaxST enzyme from Xanthomonas oryzae pv. oryzae modifies the Xoo Ax21 protein, impacting host immunity and bacterial communication.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Tyrosine sulfation is a known post-translational modification in eukaryotes.
- This modification has not been previously documented in prokaryotic organisms.
Purpose of the Study:
- To investigate the presence and function of tyrosine sulfation in prokaryotes.
- To identify bacterial enzymes responsible for tyrosine sulfation.
Main Methods:
- Development of a novel sulfotransferase assay.
- Utilizing ultraviolet photodissociation mass spectrometry for precise analysis.
- Characterization of the RaxST protein from Xanthomonas oryzae pv. oryzae.
Main Results:
- The RaxST protein was identified as a tyrosine sulfotransferase.
- RaxST was shown to catalyze the sulfation of tyrosine 22 on the Xoo Ax21 protein.
- This represents the first report of tyrosine sulfation in a prokaryotic species.
Conclusions:
- Demonstrates a novel post-translational modification in prokaryotes.
- Highlights the role of RaxST in bacterial systems.
- Suggests implications for understanding host immune responses and bacterial communication.
More Related Videos
09:31PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase
Published on: September 26, 2020
11:25Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
Published on: October 4, 2017
Related Concept Videos
Sulfur Assimilation
Bacterial Translocation and Protein Secretion
Protein Modifications in the RER
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Stringent Response in E. coli
Formation of Lipopolysaccharides
Transcription Attenuation in Prokaryotes
There are several different mechanisms used to attenuate transcription. In ribosome mediated...