Posted by: Dan | July 18, 2006

Cell division switch found to be universal for all life

Ivy Privy tipped me off to a Science Daily science release: Molecular DNA Switch Found To Be The Same For All Life. The SD writeup is pretty good, and I won’t try to top it at the moment:

The molecular machinery that starts the process by which a biological cell divides into two identical daughter cells apparently worked so well early on that evolution has conserved it across the eons in all forms of life on Earth. Researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California at Berkeley have shown that the core machinery for initiating DNA replication is the same for all three domains of life – Archaea, Bacteria and Eukarya.

In two papers that will be concurrently published in the August edition of the journal Nature Structural and Molecular Biology (now available on-line), the researchers report the identification of a helical substructure within a superfamily of proteins, called AAA+, as the molecular “initiator” of DNA replication in a bacteria, Escherichia coli (E. coli), and in a eukaryote, Drosophila melanogaster, the fruit fly. Taken with earlier research that identified AAA+ proteins at the heart of the DNA replication initiator in archaea organisms, these new findings indicate that DNA replication is an ancient event that evolved millions of years ago, prior to when Archae, Bacteria and Eukarya split into separate domains of life.

Apparently, this DNA replication initiation mechanism was so successful that it became incorporated into the process of transmission of hereditary information for cells across the entire spectrum of life.

References:

  • Nucleotide-dependent conformational changes in the DnaA-like core of the origin recognition complex. Clarey MG, Erzberger JP, Grob P, Leschziner AE, Berger JM, Nogales E, Botchan M. Nat Struct Mol Biol. 2006 Jul 9; [Epub ahead of print]. Pubmed.
  • Structural basis for ATP-dependent DnaA assembly and replication-origin remodeling. Erzberger JP, Mott ML, Berger JM. Nat Struct Mol Biol. 2006 Jul 9; [Epub ahead of print] . Pubmed.

Responses

  1. apparently worked so well early on that evolution has conserved it across the eons in all forms of life on Earth.

    Technically, it doesn’t have to work extraordinarily well in order to become evolutionarily fixed. It could be that nothing better happened to come along to replace it, or that it worked well enough and had enough of a headstart that it never got displaced. That language is in a press release though, not in the peer-reviewed papers themselves.

    I would like to point out that when Cornelius Hunter came to Cornell in April 2006, his “Gish gallop” included “DNA replication enzymes could not have had a common ancestor”.

  2. ( Psst – check your spelling in the thread title)

  3. Thanks for catching the typo.

    As for the first comment – my only point was that it was sufficient enough for its function that nothing better was required… but you’re right, it helps to be specific.


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