Sequence analysis of MLH1 protein.

1. Search human MutL protein homolog 1, Mlh1, in SWISS-PROT database. Give its (a) accession number, (b) entry name and (b) release date of last modification.

Ans: (a) primary accession number: P40692

        (b) entry name: MLH1_HUMAN

       (c) Annotations were last modified in: Release 40, October 2001

        http://www.expasy.ch/cgi-bin/niceprot.pl?P40692
2. Give its number of amino acids, molecular weight and theoretical pI.

Ans: Molecular weight: 84600.98

        Theoretical pI: 5.51

        http://tw.expasy.org/cgi-bin/pi_tool1?P40692@noft@
3. Calculate the total number of negatively charged residues and positively charged residues.
Ans: Total number of negatively charged residues (Asp + Glu): 104 

        Total number of positively charged residues (Arg + Lys): 83

        http://tw.expasy.org/cgi-bin/protparam1?P40692@noft@

4. Calculate its hydrophobicity (Kyte & Doolittle scale, window size 11, Relative weight 60%).
Ans:p

      http://tw.expasy.org/cgi-bin/protscale.pl?P40692@noft@Hphob.--/--Kyte--&--Doolittle_11_60_linear_no

5. Performe the trypsin (higher specificity) cleavage of the protein. (a) How many peptides will you get after cleavage? (b) Give the list of peptides with a mass bigger than 1000 dalton.
Ans: (a)81

        (b)

http://tw.expasy.org/cgi-bin/peptide-mass.pl