Question

d. Ampicillin resistance gene and the hygromycin resistance gene e. Ndel and Kpnl f pUC Ori and OTC-A o How can these selection markers help us to select for bacterial cells containing the pOTCA plasmid? (1 mark) ered

Answer 1

d ....ampicillin resistance gene codes for an enzyme (b-lactamase) that is secreted into the periplasmic space of the bacterium where it catalyzes hydrolysis of the b-lactam ring of the ampicillin. Thus, the gene product of the ampr gene destroys the antibiotic

Hygromycin B is an antibiotic produced by the bacterium Streptomyces hygroscopicus. It is an aminoglycoside that kills bacteria, fungi and higher eukaryotic cells by inhibiting protein synthesis. Hygromycin resistant gene produces a kinase that inhibits hygromycin by phosphorylation.

e..Ndel is an endonuclease isolated from nisseria denitrificans

NdeI is a specific Type II restriction enzyme that cuts open specific target sequences, unlike exonucleases.This enzyme is used in gene cloning to cut open reading frames in the plasmid of certain bacteria such as E. coli and insert a foreign gene.

Kpnl is type 2 restriction enzyme from klebsella pneumonia.

The function is endonucleolytic cleavage of DNA to give specific double-stranded fragments with terminal 5 end

F "pUC" is derived from the classical "p" prefix (denoting "plasmid") and the abbreviation for the University of California, where early work on the plasmid series had been conducted. It is a circular double stranded DNA and has 2686 base pairs.pUC19 is one of the most widely used vector molecules as the recombinants, or the cells into which foreign DNA has been introduced, can be easily distinguished from the non-recombinants based on color differences of colonies on growth media.

Otc plasmid is used for mitochondrial unfolded protein response.This nuclear gene encodes a mitochondrial matrix enzyme. Missense, nonsense, and frameshift mutations in this enzyme lead to ornithine transcarbamylase deficiency, which causes hyperammonemia. Since the gene for this enzyme maps close to that for Duchenne muscular dystrophy, it may play a role in that disease also.