Rare Codons Near the Beginning of a Gene Control Protein Expression Level

More Fine-Tuning

Various studies have shown that in order to produce a protein evolution would need roughly 10^70 attempts to get close enough for natural selection to take over. That is a 1 with 70 zeros after it. The number of attempts possible, on the other hand, is far less. One study concluded that 10^43 attempts may be possible. It is important to understand how tiny 10^43 is compared to 10^70. 10^43 is not about half of 10^70. It is not even close to half. In fact 10^43 is an astronomically tiny sliver of 10^70. Furthermore that study concluded that 10^43 attempts may be possible assumed, as a starting point, the existence of bacteria. In fact it assumed the Earth is covered with them. And bacteria, as every freshman knows, contain proteins. So in order to evolve a protein, evolutionists assume the prior existence of proteins, and still fail to resolve the problem. But we really haven’t even begun to address the problem.

Genes that code for proteins do not merely code for a string of amino acids that happens to perform some simple function. For beyond this, a gene codes for an incredible level of complexity. It has been discovered, for instance, that gene sequences are cleverly arranged to complement the cell’s error correction mechanisms and so minimize copying errors. On top of that information, the gene also contains signals that help to control the speed at which the new protein is synthesized. These signals have been found to be quite sophisticated.

Protein coding genes also influence how the protein synthesis process should work. Specifically, in addition to specifying the amino acids to be used in making the new protein, genes also include signals for which particular amino acid-bearing machine (the tRNA) should be used.

And once the new protein is synthesized, it must avoid the propensity of proteins to stick to each other and form fibrils in what is known as an amyloid. As one researcher explained, “The amyloid state is more like the default state of a protein, and in the absence of specific protective mechanisms, many of our proteins could fall into it.”

The problem is that short protein segments of say half a dozen amino acids can be self-complementary and sticky. If these sticky patches are on the exterior of a protein, then multiple copies of the protein can attach and form a growing and dangerous amyloid fibril.

Not surprisingly the cell has several mechanisms to protect against protein fibrillation. And beyond these protective mechanisms, the gene sequence itself arranges the protein’s amino acid sequence such that sticky patches are safely hidden away in the protein interior. This is a major threat to proteins and one evolutionist hypothesized, “Most proteins have evolved to fold in a way that effectively conceals their amyloid-prone segments.”

And there is yet more information the gene must carry. Not only must the protein not aggregate, but it may require transportation instructions that help it to be shuttled to the right place in the cell.

Also, some genes are overlapping with other genes. In other words, the stretch of DNA where a gene resides may be shared with another gene entirely. So the genetic information is now doubled. And even if this is not the case, researchers are increasingly finding that genes perform multiple tasks. In what is known as gene sharing, the protein product of a gene may carry out several separate and distinct functions. As one researcher concluded, “protein multifunctionality is more the rule than the exception.” In fact, “Perhaps all proteins perform many different functions by employing as many different mechanisms.”

Consider the p53 protein for example. It is a tumor suppressor, a gene regulator, and it plays a role in cell growth, death and DNA repair. In another example, a protein was discovered to undergo a dramatic structural and functional change. When a phosphate group is attached to the right place the protein switches from (i) helping to translate the RNA copy of a gene into a new protein to (ii) working on making the RNA copy of the gene.

So you can see that the job of evolving a protein consists of far more than merely finding a simple function, which itself is far beyond evolution’s capabilities, even according to the evolutionist’s own numbers.

Now new research reveals yet more information in the gene. It has been known for years that it is crucial that the mRNA copy of the gene is not too stable. Otherwise it cannot be used to synthesize the protein. So the gene, when transcribed by RNA polymerase, must not produce an mRNA transcript that folds up too tightly.

The new research shows that rare codons that appear early in a gene sequence influence the mRNA stability, and in so doing strongly influence that protein expression level. In other words, built into a gene sequence are instructions that can control how much of the corresponding protein to make.

One wonders how many more signals are buried in genetic sequences.