Christoph Weber's comment
>This reminds me of the old question:
>"Why are proteins so large?"
>
>My long-time suspicion was to "provide a buffer" against the cumulative effect
>of mutations and to "suppress unwanted side-reactions" (or whatever 'reaction'
>may mean in the context of non-enzymes).
>The question has never been adequately answered, as far as I know.
>
may be relevant to the editorial's "direct association of designability to
the structural elements such as superfolds". The large size of proteins may
be dictated to a degree by limited "associability" of the smaller modules.
In a slight aside, it is worth noting that a number of proteins have
multiple "functions". For example, several of the classic glycolytic
enzymes can bundle an cross-link actin filaments. There is even recent
evidence that some may have capping and severing activity as well. A lot of
the "extra" surface of proteins may have to do with their additional
functions outside the category in which we have pigeon-holed them.
Good discussion
Terry
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Terry Walsh PhD
Program Leader CRC for Diagnostic Technologies
S/Lecturer Biochemistry & Molecular Biology, School of Life Science
Queensland University of Technology, GPO Box 2434, Brisbane, 4001
AUSTRALIA Phone +61 7 3864 2347 Fax +61 7 3864 1534
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