[BiO BB] protein clustering threshold

[Iddo Friedberg]

Shamshad:

Turkey delta-crystallin has a 90% ID w/ argininosuccinate lyase. See:

NATURE Structural Biology, vol.1, No.10, Pp724-733, October, 1994 
A.Simpson,  et al.
`The structure of avian eye lens delta crystallin reveals a new fold for 
a superfamily of oligomeric enzymes'


Iddo

Shamshad Zarina wrote:
> Crystallins are very good examples for proteins having
> structural and sequence similarity but different
> functions. I work on lens protiens but I don't recall
> an example with >90% identity yet different functions.
> 
> 
> One example with less identity is of Rho-crystallin
> found in bull-frog where it acts as 'structural
> protein' to maintain lens transparency. It shows 55%
> sequence identity with Aldo-keto reductase superfamily
> which are enzymes. Both proteins have similar three
> dimensioanl structure and one residue required for
> catalytic activity is absent in rho-crystallin.
> 
> Best,
> Shamshad 
> 
> --- Iddo Friedberg <idoerg at burnham.org> wrote:
> 
>>Not to answer your question directly, 
>>just to add confusion:
>>
>>How about the same protein which performs different
>>functions?
>>Crystallins
>>are an example of a protease which, in the eye lens,
>>serves as a
>>transparent buffer.
>>
>>There are other such "moonlighting proteins" look
>>at:
>>
> 
> http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12902157&dopt=Abstract
> 
>>./I
>>
>>--
>>Iddo Friedberg, Ph.D.
>>The Burnham Institute
>>10901 N. Torrey Pines Rd.
>>La Jolla, CA 92037, USA
>>Tel: +1 (858) 646 3100 x3516
>>Fax: +1 (858) 646 3171
>>http://ffas.ljcrf.edu/~iddo
>>
>>On Fri, 6 Feb 2004, Hongyu Zhang wrote:
>>
>>
>>>Does anyone have examples of two proteins with
>>>90%
>>>identity have differenct functions? I need it as a
>>>proof to cluster a protein sequence library.
>>>
>>>Thanks!
>>>
>>>Hongyu
>>>
>>>__________________________________
>>>Do you Yahoo!?
>>>Yahoo! Finance: Get your refund fast by filing
>>
>>online.
>>
>>>http://taxes.yahoo.com/filing.html
>>>_______________________________________________
>>>BiO_Bulletin_Board maillist  - 
>>
>>BiO_Bulletin_Board at bioinformatics.org
>>
> https://bioinformatics.org/mailman/listinfo/bio_bulletin_board
> 
>>_______________________________________________
>>BiO_Bulletin_Board maillist  - 
>>BiO_Bulletin_Board at bioinformatics.org
>>
> 
> https://bioinformatics.org/mailman/listinfo/bio_bulletin_board
> 
> 
> __________________________________
> Do you Yahoo!?
> Yahoo! Finance: Get your refund fast by filing online.
> http://taxes.yahoo.com/filing.html
> _______________________________________________
> BiO_Bulletin_Board maillist  -  BiO_Bulletin_Board at bioinformatics.org
> https://bioinformatics.org/mailman/listinfo/bio_bulletin_board
> 
> 

-- 
Iddo Friedberg, Ph.D.
The Burnham Institute
10901 N. Torrey Pines Rd.
La Jolla, CA 92037
USA
Tel: +1 (858) 646 3100 x3516
Fax: +1 (858) 713 9930
http://ffas.ljcrf.edu/~iddo