amino acid sequence

by **microbe hunter** » Sun Oct 02, 2005 1:42 pm

is the amino acid sequence of protein conserved????
somebody help me pls!!!!
im stuck rite there and cant grasp the basic of genomics without the answer!!!!!

by **mith** » Sun Oct 02, 2005 5:10 pm

Can you give some context? What do you mean by conserved?

by **microbe hunter** » Mon Oct 03, 2005 4:50 am

a particular sequence of aminoacids determines the structure of a protein.so ven reaxns occur in the cell,and protein changes conformation and involves changes in active groups.so does the aminoacid sequence ever change or is it conserved???

by **lara** » Mon Oct 03, 2005 5:13 am

the same aminoacid sequence has the same conf. alwayz.but the same conf.can b due 2 diff.genetic seq.got any idea??

by **MrMistery** » Mon Oct 03, 2005 5:25 pm

Ok, i am not imposing anything here, all i am doing in this post is asking nicely: please write whole words, people that are not native english speakers, that are beginners(like my bio teacher) will not understand...

by **canalon** » Mon Oct 03, 2005 8:22 pm

lara wrote:the same aminoacid sequence has the same conf. alwayz

No. Check the prions for example. That is also why chaperones are here to help getting a correct folding for the protein.

lara wrote:but the same conf.can b due 2 diff.genetic seq.got any idea??

Yes, if the modified amino acid is replaced by an other that will not interfere with the rest of the structure it may well not alter it.

Patrick

by **lara** » Fri Oct 07, 2005 4:54 pm

d'u suggest that a given aminoacid sequence in a protein will hav > 1 conformation??

by **canalon** » Fri Oct 07, 2005 5:42 pm

lara wrote:d'u suggest that a given aminoacid sequence in a protein will hav > 1 conformation??

I am not suggesting it, I am clearly stating it.
And since the active conformation is not always the one that will be reached if folding happens spontaneously, that is why chaperones are involved into protein folding.
And Prions are another good example of proteins that have many conformations with different activities:
- "Normal" protein with its activity
- "Pathogenic" prion that lose its normal acivity for an autocatalytic activity fofolding the normal proteins in more Pathogenic one.

Patrick

by **lara** » Thu Oct 13, 2005 11:30 am

thanx but wait a sec.tell me where i go wrong.
1.polypeptide is mae from aminoacids
2.they attain the 3-dd form.fine.
here's what's puzzlin' me.the activ groups of the constituent amino acids r projected outwards,rite?will the chemical changes in these groups change the identity of the amino acids and the protein as well??

by **victor** » Thu Oct 13, 2005 11:58 am

Let me give you some example:
If mutation occurs in one of the codon triplets and causing an insertion like this:
AUG-UUU-ACA-GCA-CAG = Met-Phe-Lys-Ala-His [before mutation]

After insertion
AUG-UUU-ACA-ACG-CAG = Met-Phe-Lys-Thr-His

From this mutation, it's clear that there's a change in the chemical structure [amino-acid sequence] and it's indirectly made the chain conformation unusual or inactive...