• Question from:Jake

One of the most famous examples of a new trait evolving is the development of nylonase; an enzyme that hydrolyses nylon oligomers. Since Nylon is a man-made material, only invented in the last century, the appearance of nylonase is surely a prime example of a brand new trait evolving.

My question relates to how exactly it evolved - I've seen compelling evidence that it evolved through a gene duplication and frame shift caused by the insertion of a single base:
http://www.ncbi.nlm.nih.gov/pmc/article … 9-0153.pdf

However recently this paper was brought to my attention:
http://www.jbc.org/content/280/47/39644.long
It seems (please correct me if I'm wrong) to suggest that nylonase came about through specific amino acid changes in the active site of pre-existing esterases, which would mean that a frame-shift mutation had not occured, rather a series of specific changes to the gene.
If this is true then nylonase isn't the result of "brand new" genetic "information" it is often touted to be.

I'm not a chemist, I'm a Biology student, so the second paper was a little baffling to me, if anyone could clarify the conclusions drawn and consequences to the accepted explanation of how nylonase evolved, I would be very thankful.

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  • University of Bristol
  • Posts: 4,230

A few points to note:-

1. the original idea for a gene duplication and frame shift was published in 1983. http://www.nature.com/nature/journal/v3 … 203a0.html

2. the JBC paper you cite from 2005 is from the same group. In that paper at the end under the sections headed "Evolutionary Implication" they make it clear what the alternative suggestions are. As a general rule (which can of course be wrong) adapting an existing protein to a new function is more likely that a denovo mutation that generates a completely new reading frame. Clearly it is not possible post-hoc to say what happened but the hypothesis and the data in the JBC paper is in my view compelling.

3. The papers you cite are a good example of how science moves forward and very many times an "accepted explanation" is subsequently challenged as new information comes to light and then modified accordingly. Science like an organism grows organically and almost never stands still!