Saturday, May 23, 2020

Creation Moment 5/24/2020 - Ribosome Self-Assembly

I will praise thee; for I am fearfully and wonderfully made:
Psalm 139:14

"Scientists at the Weizmann Institute of Science in Rehovot, Israel, tried to do what ribosome does every day routinely: get all the protein and RNA parts together such that self-organization brings them all together into a functioning molecular machine. Writing in Weizmann Wonder Wander, they describe their own attempts to get the parts to self-organize, starting with the smaller of two major subunits that make up the ribosome:
As the cell’s protein factory, the ribosome is the only natural machine that manufactures its own parts. That is why understanding how the machine, itself, is made, could unlock the door to everything from understanding how life develops to designing new methods of drug production. An intensive, long research effort at the Weizmann Institute of Science has now demonstrated the self-synthesis and assembly of the small subunit of a ribosome –30S – on a surface of a chip.
Good thing they didn’t bring Darwinian evolution into the picture. Look at the challenge they faced:
Prof. Roy Bar-Ziv and Staff Scientist Dr. Shirley Shulman Daube of the Institute’s Chemical and Biological Physics
Department have been working on this project for around seven years. One of the main challenges to such a project is the sheer number of different molecules the cell must produce to make the subunit: The core is a long strand of RNA, and 20 different proteins must be attached to the strand. These get organized by the weak chemical forces between the protein molecules and the RNA – repelling at some points and attracting in others – and the whole structure thus relies on the proper manufacture and organization of each component. Add to that another six proteins that are not part of the structure, but act as chaperones to assist in the assembly. That makes a total of a least 27 different genes – one to encode each component or chaperone – that must work together to make the subunit.
Whew!
---Twenty-seven genes must be precisely encoded in order to produce 20 proteins,
---plus six chaperones to fold them,
---and a long RNA strand
---and they must be placed in position so delicately that weak chemical forces will make them come together into a working subunit.
*Even then, they get only one subunit – not a working ribosome that can translate DNA into proteins. It needs to match the large subunit, which requires even more proteins and RNA!

This is not only a chicken-and-egg problem (which came first, the ribosome or the protein?), but a positioning problem as well.
You can’t just put the parts into a sack and shake it.
They have to be placed in the correct relative positions to one another, such that the chemical forces assemble them."
CEH