Opacity genes in Neisseria gonorrhoeae: control of phase and antigenic variation
Abstract:
The chromosome of N. gonorrhoeae contains several complete expression genes coding for variant opacity proteins. DNA sequence analysis of two opacity genes derived from the same locus (opaE1) of two isogenic gonococcal variants reveals common and variable regions in these genes. Genomic blotting experiments using synthetic probes suggest gene conversion as a principle for the assembly of variant sequence information in opacity genes. The 5' region of opacity genes is composed of identical pentameric pyrimidine units (CTCTT) encoding the hydrophobic portion of the opacity leader peptide. This coding repeat is variable in a given locus with respect of the number of pentameric units. While all expression loci in a single cell are constitutively transcribed, the production of opacity proteins is determined by the coding repeat sequence on the translational level.
More Related Videos
Related Concept Videos
Transcription Attenuation in Prokaryotes
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
Diversity of Antigen Receptors
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Repressible Operon: trp Operon
Gene Regulation in Microbial Communities: Quorum Sensing
Colonisation of Pathogens
Regulation of Bacterial Virulence


