[quote name='AFJ' date='Jan 5 2011, 11:25 AM']
Would you unpack this statement.
By "unpack," do you mean elaborate?
Wikipedia goes on to list specific proteins and enzymes that require housekeeping genes. They are under the categories of transcription factors, repressors, RNA splicing enzymes, translation factors, tRNA synthases, RNA binding proteins, ribosomal proteins (49 different proteins listed for just ribosomes!), RNA polmerase (makes mRNA transript from DNA), and more.
The above are just for ribosomal proteins, regulatory proteins, and enzymes necessary for gene expression. This is where I have often asked how did the DNA evolve? In order for DNA to replicate and express protein it has to have these regulatory molecules, but it is the one that encodes them!!! SO which came first the chicken or the egg?? I'm wondering if evos get this, or even pay attention to this very important question.
And that is really just the beginning. They go on to list the housekeeping genes necesary for metbolism, like citric acid cycle enzymes, 23 enzymes for carbohydrate metabolism, lipid metaboism, amino acid metabolism, neucleotide synthesis...and I just a hit something that may be worthy of a seperate post....
DNA housekeeping genes also encode for the very complex enzymes of the electron transfer chain located in the mitochondria. This is where and how ATP is produced.
1. NADH dehydrogenase has 8 different housekeeping genes listed at wiki. According to: http://en.wikipedia....H_dehydrogenase
NADH dehy has 45 subunits in mammals!! Think of this. This is 45 different peptide chains all bonded together just right in order to catalyze the first chemical reactions in the electron tranfer chain, on it's way to ATP syntase.
2. Cytochrome C Oxidase has several very interesting facts.
It has 12 different housekeeping genes listed at wiki, three of which are encoded by mitochondrial DNA. I can tell you why I would not interpret this as a confirmation of the endosymbiosis theory, that the mitochondria was at one time an undigested bacteria swallowed into an ancestor cell. Namely because nuclear DNA (located in the nucleus) encodes for proteins that make up the mitochondria. You will find them in this same list--
Mitochrondrial Housekeeping Genes
So we have nuclear DNA encoding for the mitochondrial protein/enzymes, and visa versa. Does anyone have a just so story for that one???
At any rate, Cyt C oxidase has 13 subunits, and produces the third step of the four in the electron transport chain-- just before ATP sythase.
3. ATP synthase--Produces the ATP molecule. Eight housekeeping genes listed. I'm assuming from the list of encoding genes under ATP synthase, human has 27 subunits. Although keep in mind this is a very "conserved" enzyme. DUH! It has the same function in bacteria as it does in us. It has to do the same chemical reactions in plants, as it does in us.
I found this very amusing under "The Evolution of ATP Syntase"
Say no more. It has to do the same thing, so it's built the same.
Well, I hope I unpacked it enough Bruce V. There's so much one do an indepth study on, but I think it easy to see that there is valid reason for duplication in genes. Namely, need. It seriously doubt it happened by unguided forces. All genes have copies, but those that are needed more are more numerous. This makes sense to me, and scores for design.
Thank you for your elaborating. Many Evo's believe that if we can figure out how DNA evolved then we know how life came from non life. But as you showed, DNA is not enough. DNA is only the information but for it work it requires an integrated system: ribosomes, housekeeping genes, ATP,enzymes... Evo's get around this by starting evolution after abiogeneis.