In <1993Sep9.151124.8214 at gserv1.dl.ac.uk> CS at at.ac.univie.abc ("Christoph Schller") writes:
>I am working with the Saccharomyces Catalase genes. Till now I did
>only transcriptional regulation studies but I am also interested in
>the physiological function of this enzymes. Deletion of all catalase
>genes in S.c. gives no phenotype (at least under lab conditions).
>My question is: Is catalase an important enzyme in any biological
>system? Under which conditions and in what context is Catalase
>Thank you very much.
Deletion of the catalase gene yielding no phenotype doesn'
REALLY surprise me, if you look only at "lab conditions." Catalase
is responsible for eliminating hydrogen peroxide by converting it to
water and oxygen. Most cells have other enzymes which also
contribute to this activity, e.g. glutathione peroxidase (RBC's),
and cytochrome c peroxidase (if memory serves me right). So, al
long as levels of oxidative stress are very low, there should be no
problem. Compare their survival when exposed to hydrogen peroxide,
and I expect that you would see the yeast die at much lower
concentrations when it doesn't have catalase.