Contents

Negative Transcription Regulation in Prokaryotes

How do bacteria avoid wasteful production of unnecessary proteins when their genes are always on? The answer lies in regulating the operon.

Operons and Prokaryotic Gene Regulation

How do bacteria adapt so quickly to their environments? Part of the answer to this question lies in clusters of coregulated genes called operons.

Simultaneous Gene Transcription and Translation in Bacteria

How would you make transcription and translation work when you no longer have a nucleus? Bacteria have an interesting answer.

Attenuation in the control of expression of bacterial operons

Bacterial operons concerned with the biosynthesis of amino acids are often controlled by a process of attenuation. The translation product of the initial segment of the transcript of each operon is a peptide rich in the amino acid that the particular operon controls. If the amino acid is in short supply translation is stalled at the relevant codons of the transcript long enough for the succeeding segment of the transcript to form secondary structures that allow the transcribing RNA polymerase molecule to proceed through a site that otherwise dictates termination of transcription. This site is the attenuator; the process is attenuation.

Genome Packaging in Prokaryotes: the Circular Chromosome of E. coli

How do bacteria, lacking a nucleus, organize and pack their genome into the cell? Supercoiling enables this but forces a different kind of transcription and translation in prokaryotes.

Simple Viral and Bacterial Genomes

How do genomes from E. coli and yeast help researchers? They shed light on the basic principles of genomics. The Human Microbiome Project sequences microbial genomes for this purpose.

Genetics of the Influenza Virus

Periodically, the yearly flu transforms into a particularly virulent strain, like the Spanish flu that killed millions of people in 1918. How do these pandemic strains arise?

Genetic Origins of Microbial Virulence

How do scientists discover which genes make pathogenic microbes particularly virulent? In other words, why doesn't eating raw oysters always kill us?

Antibiotic Resistance, Mutation Rates and MRSA

In bacteria, mutations in plasmids can accumulate surprisingly fast. What does this mean for us humans, who have to fight with these new antibiotic resistant strains?