Monday, March 15, 2010

DNA Repair Proteins: Efficiently Finding Genome Errors

The heroics of the cell's DNA repair system are well known, but new research is adding yet another incredible facet to the story. Experimentalists tagged DNA repair proteins with nanocrystals that light up. They then observed how they interact with DNA molecules. As reported:

They watched while UvrA proteins randomly jumped from one DNA molecule to the next, holding on to one spot for about seven seconds before hopping to another site. But when UvrA formed a complex with two UvrB molecules (UvrAB), a new and more efficient search technique emerged: the complex slid along the DNA tightrope for as long as 40 seconds before detaching itself and jumping to another molecule. ... In addition to random jumping and sliding, the researchers also observed what they called "paused motion," in which UvrAB's motion seemed slower and purposeful.

Proteins certainly do perform remarkable functions. As one researcher explained:

How this system works is an important unanswered question in this field. It has to be able to identify very small mistakes in a 3-dimensional morass of gene strands. It's akin to spotting potholes on every street all over the country and getting them fixed before the next rush hour.

It would be extremely unlikely for blind variations to stumble upon such protein designs. With evolution we must believe that such proteins just happened to arise and then were selected because they helped in the DNA repair system. If you believe that then I have a bridge to sell you.

6 comments:

  1. Blind molecules can't identify anything, let alone correct mistakes.

    To identify and correct mistakes requires knowledge.

    This knowledge is most likely in the form of a program similar to spellchecker.

    IOW it is in the software of life- DNA being part of the hardware.

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  2. Yeah, it's quite complex.

    So, what hypothesis do you...

    err, um, never mind.

    The referenced Molecular Cell article can be found at...
    http://www.cell.com/molecular-cell/abstract/S1097-2765(10)00117-6

    The original source is not freely available but, personally, I will readily agree this is evidence of complexity and organization that suggests some hereto unknown aspect of life processes.

    My hypothesis for this involves life being quantum-based.

    I suggest this hypothesis is even fairly religion neutral in that allows for God’s existence.

    For example, see my “A God Hypothesis” from a previous thread.

    http://darwins-god.blogspot.com/2010/03/evolution-creates-evolution-as-fire.html?showComment=1268512821057#c4401994234143392014

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  3. Thought:

    ====
    Yeah, it's quite complex.

    So, what hypothesis do you...

    err, um, never mind.
    ====

    The problem is not that he did not give his hypothesis, the problem is that you don't acknowledge it.

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  4. From the abstract- thanks Dave-

    "How DNA repair proteins sort through a genome for damage is one of the fundamental unanswered questions in this field."

    And that is because of the way it is being approached.

    Until it is approached from a design perspective it will remain a mystery.

    That is because the system is software controlled.

    Software only ID says exists...

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  5. This comment has been removed by the author.

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  6. Hi Cornelius Hunter,

    You wrote...
    "The problem is not that he did not give his hypothesis, the problem is that you don't acknowledge it."

    Which "he" are you talking about, the author of the Science Daily article or the five scientists who participated in the experiment?

    I didn't even see a reference to "evolution" from either source. However, it doesn't matter, since I am not about to let scientists make my conclusions for me even if they did the hard work of obtaining the data. I'm definitely not going to let a populist publisher do my thinking for me either.

    It's easy to throw stones at someone else's hypothesis without offering an alternative.

    It is even easier to throw stones at vague boogiemen regardless of how real the feeling of fear is.

    My hypothesis is the presumption that life and life processes evolved over billions of years is historically accurate. This would include the DNA repair process.

    However, I don't believe true randomness exists.

    Instead, I suggest life is quantum-based and the organized appearance of life (i.e. specified complexity) is the result of interconnected and orchestrated quantum effects.

    Since I also think consciousness is the result of organized quantum effects, it wouldn't be inaccurate to say life is consciously "designed".

    I am following the evidence wherever it leads. There is scientific support for this hypothesis (Quantum Biophysics) with more supporting evidence being discovered every day.

    What's more important, following the evidence and exploring alternative explanations or fighting the Culture War?

    Have you absolutely no interest in exploring the alternative explanation I have been forwarding on your blog?

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