What would be the phenotype of an E. coli strain in which the tandem tryptophan codons in the leader region were mutated so that they coded for serine instead?

In E. coli, the gene bioD+ encodes an enzyme involved in biotin synthesis, and galK+ encodes an enzyme involved in galactose utilization. An E. coli strain that contained wild-type versions of both genes was infected with P1 phage, and then a P1 lysate was obtained. This lysate was used totransduce (infect) a strain that was bioD− and galK−. The cellswere plated on a medium containing galactose as the sole carbonsource for growth to select for transduction of the galK+ gene.This medium also was supplemented with biotin. The resultingcolonies were then restreaked on a medium that lacked biotin tosee if the bioD+ gene had been cotransduced. The following resultswere obtained:What information do you know based onthe question and your understanding of the topic?

Would increasing the concentration of salt prevent the mutant protein from aggregating?

You are examining the processing of rRNA in E. Coli using a Northern blot. Normally, a 30S rRNA transcript is transcribed and then processed (cleaved) into 23S, 16S, and 5S mature rRNAs. You suspect the gene RPO7 is involved, so you make a mutant strain of bacteria and compare it to a Wild-type (Wt) strain. You run RNA extracts from the two strains on a Northern blot and probe it with a radioactive probe that binds to all rRNA. You get the following results.

n yeast cells, telomerase remains active and maintains telomeres of about 300 base pairs. Propose what would happen to the telomeres over time in a yeast lineage in which the following mutations were created.  The template portion of the telomerase RNA is changed from 5’-ACACCCACA to 5’-ACAUCUACA.

A graduate student studying the pathogenic bacteria Acinetobacter baumannii made cDNA from planktonic cells and biofilm cells and performed RNA-Seq on both samples. She aligned her sequencing reads to a locus of the baumannii genome as shown. a. Which genes are on an operon together? Explain which data supports this? b. What is the most expressed transcript from the locus in Planktonic culture? c. Order the transcripts from largest increase in relative expression between biofilm and planktonic cells to the largest decrease in relative expression. d. When this data was compared to microarray transcriptional profiling, the microarray data provided lower expression levels for the most highly expressed transcripts. Why did this occur?

Explain how the presence of tryptophan favors the formation of the 3–4 stem-loop.

If a wild-type (normal, NOTmutated) E. coli strain is grown in a medium: a. without lactose or glucose, how many proteins (and which ones) are bound to the lac operon? b. Without lactose, but with glucose, how many proteins (and which ones) are bound to the lac operon??

A possible forward primer to be designed is a primer that binds to the region of the OXA-M290 gene where the start codon is located, and the reverse primer is the primer that binds to the region of the gene where the stop codon is located.  In order to clone the PCR product generated using these primers into pET-28a, extra nucleotides must be added to the 5' ends of the primers. These extra nucleotides will contain the recognition sites for the restriction enzymes that are used for cloning. When the DNA produced by PCR using these primers is treated with the restriction enzymes, this will generate sticky ends at the ends of the PCR product. If pET-28a is digested with the same restriction enzymes, the sticky ends of the PCR product will bind to the sticky ends on the digested pET-28a, allowing the two DNA molecules to be connected together by DNA ligase. Which primer (forward or reverse) should contain the SacI recognition site, and which primer (forward or reverse) should contain the…

With regard to TNRE, what is meant by the term anticipation?