
Ribosomes as Productive Nanosystems - ph0rque
http://metamodern.com/2009/07/16/4435/
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biohacker42
_Ribosomes are productive nanosystems, that is, machines that combine small
molecular building blocks under digital control to build complex structures._

Digital control?

 _They’re programmable by means of genetic engineering_

Mmmm... they're _hackable_ by means of genetic engineering. Programmable for
me still means you can build exactly what you want from scratch.

 _based on structures determined by x-ray crystallography_

x-ray crystallography is a dark and mysterious art, no seriously it is, it's a
close to vodoo as any science can be.

 _Regarding catalysis: There’s none, in the usual chemical sense — ribosomes
merely provide positional control that produces a high effective concentration
of the right reactive molecules in the right place at the right time, thereby
implementing the most straightforward kind of mechanosynthesis._

I'm pretty sure there may be some quantum tunneling going on.

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TrevorJ
Re: programmable - is it safe to assume that given sufficient understanding of
DNA and biology one could in fact build what they want from scratch?

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alex_stoddard
It would depend on how fancy you can get with engineering custom [transfer
RNAs] (<http://en.wikipedia.org/wiki/Transfer_RNA>), which are the bridge
between the genetic code and the proteins that get made at ribosomes.

Within the limits of the chemistry one could get to work I see no a priori
reason why something other than amino-acids (the building blocks of proteins)
couldn't be attached to the tRNAs.

Proteins have the additional very valuable property of being essentially self-
assembling - the 3D structures or proteins form inherently from their linear
sequence of amino acids. That is one of the key reasons why a linear genetic
code works to produce all the many varied proteins in living things.

~~~
biohacker42
_Proteins have the additional very valuable property of being essentially
self-assembling_

Chaperone proteins? <http://en.wikipedia.org/wiki/Chaperone_(protein)>

~~~
alex_stoddard
I was hedging with "essentially". I didn't want to make an already biogeeky
post too obscure. Some proteins can renature without chaperones.

Also to quote the wikipedia article, "Chaperones do not necessarily convey
steric information required for proteins to fold: thus statements of the form
`chaperones fold proteins` can be misleading."

