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Author Topic:   The origin and evolution of protein superfamilies
mark24
Member (Idle past 3298 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 1 of 5 (19327)
10-08-2002 12:10 PM


Abstract FYI.

"The origin and evolution of protein superfamilies.

Dayhoff MO.

The organization of proteins into superfamilies based primarily on their sequences is introduced: examples are given of the methods used to cluster the related sequences and to elucidate the evolutionary history of the corresponding genes within each superfamily. Within the framework of this organization, the amount of sequence information currently and potentially available in all living forms can be discussed. The 116 superfamilies already sampled reflect possibly 10% of the total number. There are related proteins from many species in all of these superfamilies, suggesting that the origin of a new superfamily is rare indeed. The proteins so far sequenced are so rigorously conserved by the evolutionary process that we would expect to recognize as related descendants of any protein found in the ancestral vertebrate. The evolutionary history of the thyrotropin-gonadotropin beta chain superfamily is discussed in detail as an example. Some proteins are so constrained in structure that related forms can be recognized in prokaryotes and eukaryotes. Evolution in these superfamilies can be traced back close to the origin of life itself. From the evolutionary tree of the c-type cytochromes the identity of the prokaryote types involved in the symbiotic origin of mitochondria and chloroplasts begins to emerge."

I don't have access to the whole paper, unfortunately, but it should interest TB.

Mark

------------------
Occam's razor is not for shaving with.


Replies to this message:
 Message 2 by Tranquility Base, posted 10-08-2002 10:03 PM mark24 has responded

    
Tranquility Base
Inactive Member


Message 2 of 5 (19351)
10-08-2002 10:03 PM
Reply to: Message 1 by mark24
10-08-2002 12:10 PM


^ This paper (from 1976 BTW) is one of the seminal papers identifying the superfamilies. Dayhoff is a famous seqeunce analysis guy who I cite in my lectures.

Superfamilies have conserved 3D structres and frequently little or no seqeunce similarity that is conserved across the family.

The statements made in this abstract are supersitions that presume evolution.

It does not discuss the acual origin of each family but the evolution within the families! Most papers on 'origin of families' are misleading entitled - they are talking about how the families spread out from a parent gene.

Gene families themselves are subsets of superfamiles or are at the superfamily level themselves. Families within superfamilies may or may not be convergent from an evolutionary POV.

[This message has been edited by Tranquility Base, 10-08-2002]


This message is a reply to:
 Message 1 by mark24, posted 10-08-2002 12:10 PM mark24 has responded

Replies to this message:
 Message 3 by mark24, posted 10-09-2002 11:14 AM Tranquility Base has responded

  
mark24
Member (Idle past 3298 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 3 of 5 (19407)
10-09-2002 11:14 AM
Reply to: Message 2 by Tranquility Base
10-08-2002 10:03 PM


quote:
This paper (from 1976 BTW) is one of the seminal papers identifying the superfamilies. Dayhoff is a famous seqeunce analysis guy who I cite in my lectures.

TB,

Ah, I thought I'd stumbled across something you never knew It was wierd, I found it in a list of paleosol/geology links & thought it worth following up.

Mark

------------------
Occam's razor is not for shaving with.


This message is a reply to:
 Message 2 by Tranquility Base, posted 10-08-2002 10:03 PM Tranquility Base has responded

Replies to this message:
 Message 4 by Tranquility Base, posted 10-09-2002 9:08 PM mark24 has not yet responded

    
Tranquility Base
Inactive Member


Message 4 of 5 (19447)
10-09-2002 9:08 PM
Reply to: Message 3 by mark24
10-09-2002 11:14 AM


^ Thanks for pointing it out. You found it amongst paleosol links?

I come across recent papers like this too but almost without exception the 'origin' they are talking about is the origin of diversification within the families.


This message is a reply to:
 Message 3 by mark24, posted 10-09-2002 11:14 AM mark24 has not yet responded

Replies to this message:
 Message 5 by derwood, posted 10-11-2002 2:04 PM Tranquility Base has not yet responded

  
derwood
Member
Posts: 1457
Joined: 12-27-2001


Message 5 of 5 (19646)
10-11-2002 2:04 PM
Reply to: Message 4 by Tranquility Base
10-09-2002 9:08 PM


quote:
Originally posted by Tranquility Base:
^ Thanks for pointing it out. You found it amongst paleosol links?

I come across recent papers like this too but almost without exception the 'origin' they are talking about is the origin of diversification within the families.


Yeah, obviously that is because all of the families were created ex nihilo by the deity described in the Old Testament... Or is it the New Testament?

I hope it is the new god in the New Testament - the one in the OT is pretty scary...


This message is a reply to:
 Message 4 by Tranquility Base, posted 10-09-2002 9:08 PM Tranquility Base has not yet responded

    
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