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Metabolic pathways and their enzymes
- Open
the PATHWAY database
(or go to the front page of SRS6,
select ‘metabolic pathways’) and move on to the Query form.
- Search
a metabolic pathway; for instance, ‘glycolysis’, or ‘purine’ (metabolism).
- Submit
the query to return the variety of organisms from which the pathway
is known in greatest detail (for instance, Homo sapiens, or
E. coli).
- Observe
that not many other vertebrates are known in great depth in this regard.
As a possible exercise, you could observe whether the same steps, (i.e.,
enzymes, substrates, reaction products) have occurred in a group of
species.
- You
could conceivably think of ‘aligning’ metabolic pathways and speculate
on possible inter-specific differences. Do you see any interest in this
exercise? If not, you could consult Dandekar T. et al. Pathway Alignment;
application to the comparative analysis of glycolytic enzymes. Biochem.
J. (1999) 343, 115-124.
- As
another possible exercise, you could select one given enzyme catalyzing
a particular step and align the sequence of the protein from several
different species, observing what is conserved and what varies among
taxonomic groups or species. For instance, find the enzymes phosphofructokinase,
pyruvate kinase or aldolase in Helicobacter
pylori, E. coli and Mycoplasma hominis.
- If you are working with enzymes, you may be interested in consulting
BRENDA,
where specific physical and chemical characteristics of enzymes are
referenced.
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