Understanding Gene Sequences

It is obvious in situations like this that a clear phylogenetic picture is necessary in order to gain some understanding of the distributional history of the taxa in question, in this case the plicataloside-positive ones. This would appear to be a situation where gene sequence information might well provide the needed framework. It would also be of interest to learn where the biosynthesis of plicataloside diverges from the pathway that leads to the anthrones normally seen in Aloe. 

When we have the information from the sequencing of the human genome, and want to understand the properties of those proteins that are coded by some of the genes but not yet known experimentally, we need to solve the protein-folding problem. Then we can translate the gene sequence—which specifies the sequence of amino acids—into the three-dimensional structure of the unknown protein. 

Genomics is the complete understanding of all the locations and sequences in the tens of thousands of genes in humans. What are the functions associated with these sequences What proteins are made from these gene sequences, what are their onedimensional strings and three-dimensional architectures when folded appropriately Can we use this knowledge to diagnose diseases, and to make material to cure these diseases ... 

The determination of the genome and the transcriptome did not rely much on mass spectrometry, other techniques allowing the gene sequence to be reached more efficiently. For the proteome, at the contrary, mass spectrometry has a central role. No other technique can compete with its efficiency to determine protein sequence quickly on very low sample quantities. But knowledge of the genome, the transcriptome and the proteome does not reveal the phenotype of a living system, as it is difficult or impossible to establish a direct link between the protein and its enzymatic activity, and thus the produced metabolites. There is almost no way to predict the substrates and metabolites of unknown enzymes whose total sequence is known. And it often appears that even for known enzymes the known activities are only partial. To understand the cell, it is thus an essential task to link the expression of proteins to the produced metabolites. 

Uberbacher, E. C Xu, Y. Mural, R. J. (1996). Discovering and understanding genes in human DNA sequence using GRAIL. Methods Enzymol 266,259-81. 

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