Related Experiment Video
Updated: Aug 19, 2026

Immuno-fluorescence Assay of Leptospiral Surface-exposed Proteins
Published on: July 1, 2011
Identification of an EF-Tu protein that is periplasm-associated and processed in Neisseria gonorrhoeae
S F Porcella1, R J Belland, R C Judd
1Department of Microbiology, University of Texas Southwestern Medical School at Dallas 75235, USA. porcella@utsw.swmed.edu
Abstract:
A 44 kDa protein is a dominant component of periplasmic extracts of Neisseria gonorrhoeae. Peptide sequence generated from a cyanogen-bromide-cleaved fragment of this protein indicated sequence homology with elongation factor-Tu (EF-Tu). Polyclonal antiserum was made against the 44 kDa protein purified from periplasm extracts of N. gonorrhoeae. The preabsorbed antiserum was immunoblotted against whole-cell lysates on two-dimensional gels. A 44 kDa protein and a smaller 37 kDa protein were recognized by this antiserum. A N. gonorrhoeae gamma phage DNA library was screened and a clone expressing a 44 kDa protein was identified. The DNA insert in this clone contained several genes homologous to genes contained in the str operon of Escherichia coli. One ORF product with a calculated molecular mass of 43 kDa was highly homologous to the EF-TuA of E. coli. A synthetic peptide antiserum specific for a portion of the C terminus of EF-Tu confirmed that the 37 kDa protein in whole-cell lysates of N. gonorrhoeae was a processed form of EF-Tu. Deletion of the tufA gene homologue in N. gonorrhoeae was attempted but was unsuccessful.
More Related Videos
14:58Identification of Protein Complexes in Escherichia coli using Sequential Peptide Affinity Purification in Combination with Tandem Mass Spectrometry
Published on: November 12, 2012
11:33Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
Related Concept Videos
Directing Proteins to the Rough Endoplasmic Reticulum
Insertion of Single-pass Transmembrane Proteins in the RER
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Tail-anchoring of Proteins in the ER Membrane
GPI Anchoring of Proteins in the ER Membrane
GPI-anchor structure
A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
Protein Translocation Machinery on the ER Membrane
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.
Bacterial Translocation and Protein Secretion