The only available tool which i know is https://pir.georgetown.edu/pirwww/search/comp_mw.shtml.

It can accept multiple uniprot ids and fasta sequences.

Thank you Abdul,

the graphical output looks great, unfortunately results seems not to be exportable from this tool in tabular form for further analyses.

You can simply do that in excel. Say, you have the sequences in column A; and you want to count Tyr (Y) in column B. So, in B1 write this formula:

=len(A1)-len(substitute(A1,"Y",""))

Then, auto-fill the column B. That't it. Column B now has the Tyr composition of the sets of proteins listed in column A. Repeat it with other amino acids. You can even automate that process too, if you write the amino acid codes in a row and use the cell pointer in the above mentioned formula.

Thank you very much Uttam Pal,

it is simple, quick and brilliant solution. Save me lot of time.

I will use it in this form to obtain percent values:

=100*(len(A1)-len(substitute(A1,"Y","")))/len(A1)

But there is a small problem, if I paste my sequence(s) into cell(s), then Excel count some extra characters - for example for protein DNMT1 which has 1616 amino acid residues, Excel counts length of 1642 aa.

I have no idea how to fix this issue.

Thanks

Most probably, you are pasting the the sequence in fasta format (80 characters per line followed by a invisible newline character). In that case it is probably counting the newline characters too.

In Linux actually you can get rid of these newline characters very easily. In Linux, you can replace (Ctrl+H) newline characters (\n) with blank, using any text editors.

P.S. You can do this in LibreOffice Cal (similar to MS office but free) as well, which works in windows too. Just click Ctrl+H and in the replace dialogue box type \n and in advanced option check Regular expressions. (Screenshot attached)

Yes, you are right, I have controlled it and in my system (Windows) each line has 60 characters, so I thought this command will fix it:

=len(A1)-(len(A1)/60)

but NOT, the result of protein length is 1614,633 instead of 1616 as I naively thought.

Thank you very much Uttam Pal,

I am just downloading LibreOffice Cal and then proceed according to your instruction :-)

All the best